Re: [Pw_forum] Raman

[xirainbow]

Use LDA instead of GGA.

On Wed, Dec 9, 2015 at 7:25 AM, Mofrad, Amir Mehdi (MU-Student)
 wrote:
> Dear Quantum Espresso users and developers,
>
>
> Does anyone know that Quantum Espresso is capable of calculating Raman
> intensities? When I want to do the phonon calculations I get the following
> error:
>
>
> error: task # 0
>  from phq_setup : error # 1
>  third order derivatives not implemented with GGA
>
> According to what is provided on the Quantum Espresso website, Raman
> calculations work only with NC pseudo-potentials and I tried to use that
> kind of PP in my scf calculations. Below is my scf and phonon calculations
> input files. Any help would be thoroughly appreciated on how to get Raman
> intensities.
>
>
> SCF INPUT:
>
>  &CONTROL
>  calculation = 'scf' ,
>  restart_mode = 'from_scratch' ,
>  wf_collect = .true. ,
>  outdir = './scratch' ,
>  wfcdir = './scratch' ,
>  pseudo_dir = '/global/espresso/pseudo' ,
>  prefix = 'SOD' ,
>  verbosity = 'high' ,
>  etot_conv_thr = 1e-5 ,
>  forc_conv_thr = 1e-4 ,
>  nstep = 50 ,
>  tstress = .true. ,
>  tprnfor = .true. ,
>
>  /
>
>  &SYSTEM
>  ibrav = 0,
>  nat = 36,
>  ntyp = 2,
>  ecutwfc = 50 ,
>  ecutrho = 200 ,
>
> /
>
>  &ELECTRONS
>   electron_maxstep = 100,
>   conv_thr = 3e-8 ,
>   mixing_mode = 'plain' ,
>   mixing_beta = 0.7 ,
>   diagonalization = 'david' ,
>
> /
> CELL_PARAMETERS bohr
>  16.7202967500.00.0
>  0.0   16.7202967500.0
>  0.00.0   16.720296750
> ATOMIC_SPECIES
>Si   28.08600  Si.tpss-mt.UPF
> O   15.99940  O.tpss-mt.UPF
> ATOMIC_POSITIONS angstrom
>  Si  2.2114340870.04.42400
>Si  6.6365659130.04.42400
>Si  4.424002.2114340870.0
>Si  4.424006.6365659130.0
>Si  0.04.424002.211434087
>Si  0.04.424006.636565913
>Si  2.2114241384.42400   -0.0
>Si  6.6365758624.42400   -0.0
>Si  0.02.2114241384.42400
>Si  0.06.6365758624.42400
>Si  4.424000.02.211424138
>Si  4.424000.06.636575862
> O  1.2872841424.0775133401.287298380
> O  7.5607158584.7704866601.287298380
> O  7.5607158584.0775133407.560701620
> O  1.2872841424.7704866607.560701620
> O  1.2872983801.2872841424.077513340
> O  1.2872983807.5607158584.770486660
> O  7.5607016207.5607158584.077513340
> O  7.5607016201.2872841424.770486660
> O  4.0775133401.2872983801.287284142
> O  4.7704866601.2872983807.560715858
> O  4.0775133407.5607016207.560715858
> O  4.7704866607.5607016201.287284142
> O  8.5066504985.7138707755.713853509
> O  0.3413495023.1341292255.713853509
> O  8.5066504983.1341292253.134146491
> O  0.3413495025.7138707753.134146491
> O  5.7138707755.7138535098.506650498
> O  3.1341292255.7138535090.341349502
> O  3.1341292253.1341464918.506650498
> O  5.7138707753.1341464910.341349502
> O  5.7138535098.5066504985.713870775
> O  5.7138535090.3413495023.134129225
> O  3.1341464918.5066504983.134129225
> O  3.1341464910.3413495025.713870775
> K_POINTS automatic
> 4 4 4   1 1 1
>
> Phonon Input File
>
>
> phonons of Sodalite at Gamma
> &inputph
> tr2_ph= 1e-14,
> prefix= 'SOD',
> amass(1)  =  28.08600,
> amass(2)  =  15.9940,
> outdir= './scratch/',
> fildyn= 'SOD.dyn',
> recover   = .false.,
> epsil = .true.,
> lraman= .true.,
> trans = .true.,
> max_seconds   = 35
> /
> 0.0 0.0 0.0
>
> Best regards,
>
>
> Amir M. Mofrad
>
> University of Missouri
>
>
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> http://pwscf.org/mailman/listinfo/pw_forum



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Hui Wang
School of physics, Henan University of Science and Technology, Henan, China
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Re: [Pw_forum] Raman and IR spectra

[xirainbow]

IR and Raman calculation in QE is based on perturbation.
Unfortunately, metal can not be treated by perturbation theory.

On 10/27/15, Gul Rahman  wrote:
> Dear All,
> Is it possible to calculate the Raman and IR spectra of metallic clusters
> with QE. I heard it is possible to calculate it for semiconductors, but not
> for metallic.
> Why QE is not able to calculate IR and Raman spectra of a metallic system.
> Thanks,
> Gul
>
>
> --
>
>
> Dr. Gul Rahman
> Assistant Professor,
> Department of Physics,
> Quaid-i-Azam University,
> Islamabad, Pakistan
> http://www.qau.edu.pk/profile.php?id=818020
>


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Hui Wang
School of physics, Henan University of Science and Technology, Henan, China
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Re: [Pw_forum] band gap at Gamma point in primitive cell different from the band gap at Gamma point in conventional cell

[xirainbow]

Your condition is normal.
The Brillouin zone folding must change the electronic gap.

On Mon, Oct 6, 2014 at 11:15 AM, Juliana Morbec  wrote:
> Dear All.
>
> I have tried to calculate the band gap of Ta3N5. When I use the primitive
> cell with 16 atoms I obtain a band gap of 1.68 eV at the Gamma point;
> however, when I use the conventional cell with 32 atoms, I find a band gap
> of 1.34 eV at the Gamma point. I have already checked the convergence of
> both calculations with respect to the energy cutoff and the k-point grid.
>
> I was wondering if this could be related to the Brillouin zone folding. Do
> anyone have any idea why I obtain too different values at the same point?
>
> I will really appreciate any help in this issue.
>
> Best wishes,
>
> Juliana Morbec
> -
> Juliana M. Morbec, Ph.D.
> Postdoctoral Researcher
> Institute for Molecular Engineering, The University of Chicago
>
>
>
>
>
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Hui Wang
School of physics, Henan University of Science and Technology, Henan, China
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[Pw_forum] ignoring the antiferromagnetic order in the symmetry analysis of phonons

[xirainbow]

> Is it possible to ignore the antiferromagnetic order in the symmetry
> analysis of the phonons?
  I do not think QE can do it now.

-- 

Hui Wang
School of physics, Henan University of Science and Technology, Henan, China

[Pw_forum] Can we obtain spectra after running ph.x in QE?

[xirainbow]

> Is that possible to show or draw a (e.g.Raman or Infrared ) spectrum after  
> phonon calculations (ph.x).
  QE can not do it directly. You must write code to do it.

[Pw_forum] nosym vs. nosym_evc

[xirainbow]

>  Does nosym = .true. make noinv = .true
No.
The nosym controls the space group symmetry. But noinv
controls the time reversal symmetry. They are totally different.

[Pw_forum] LO-TO splitting in molecules

[xirainbow]

> I am not sure weather LO-TO splitting could be observed in molecules.
 I do not think so. LO-TO splitting originates from the long
range coulomb interaction and ordered dipole vibration. The latter
does not exist in molecular.

> My  Further qusetion regarding the RAMAN modes.  Whether pure Raman modes 
> (i.e.
> Infrared inactive modes and only Raman acive)  will give any LO-TO splitting.
 No.

[Pw_forum] info Raman spectrum

[xirainbow]

> - which kind of pseudopotential  should i use? ultrasoft or norm conserving?;
  Only norm conserving.

>   ?relaxed the structure (pw.x);
>   ?scf of the structure with the new positions (pw.x);
>   ? ph.x with  turn on;
>   ? used dynmat.x for obtaining the frequencies mode.
   yes.

[Pw_forum] phonon frequencies ....

[xirainbow]

The number of modes at every k point must be 3*n.(n is the number of atoms)
Please check your output file carefully.

On Tue, Jul 22, 2014 at 2:13 AM, Shyam Khambholja
 wrote:
> Dear users,
>
> while calculating phonon frequencies at high pressure, some modes in optical
> branches disappear. can anybody tell me why this happen ? or is it my
> calculation error ?
>
> Thanks & regards,
>
>
> Dr. Shyam G Khambholja,
> Indus University
> Gujarat
> India
>
>
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Hui Wang
School of physics, Henan University of Science and Technology, Henan, China

[Pw_forum] Regarding LA-TA modes

[xirainbow]

> Is it possible to get non zero acoustic modes at Gamma point.
NO.

Please read books about lattice dynamics, for example "Poulet H,
Mathieu JP. Vibration Spectra and Symmetry of Crystals: Science
Publishers, Inc., 1976."

On Sat, Jul 12, 2014 at 10:38 PM, Kondaiah Samudrala
 wrote:
> Dear all,
>
> I am very much interested in knowing  LA-TA modes and grunessian parameter
> calculations using pwscf.
>
> Is it possible to get non zero acoustic modes at Gamma point. Because, If I
> am applying asr rule at gamma point, the acoustic modes are zero in my case.
> How can we define LA-TA modes ???
>
> Is degenerative modes (Out of First three modes)  are transverse modes???
>
> How to do grunessinn parameter calculations for entire phonon spectrum  in
> PWscf???
>
> Hope positive reply..Thanks in advance
>
> with regards
> S. Appalakondaiah
> PhD student
> University of Hyderabad
>
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Hui Wang
School of physics, Henan University of Science and Technology, Henan, China

[Pw_forum] Band structure of graphene

[xirainbow]

Is the Fermi energy around -7.5 eV?


On Thu, May 22, 2014 at 2:30 PM, Pooja Dhorge  wrote:

> Dear PWSCF users,
>
>  I got stuck in calculating the correct band structure of
> graphene (single layer). Below I am giving my input files. I'm also
> inserting the image of band structure  that I have got from the below given
> inputs.
> ?
>
>
> *1) cc.scf.in  *
> &control
> calculation='scf'
> restart_mode='from_scratch',
> prefix= 'cc'
> pseudo_dir = '/home/pooja/workspace/src/qe/espresso-5.0.2/pseudo/',
> outdir='./out'
> /
> &SYSTEM
> ibrav = 4,
> celldm(1) = 4.608737,
> celldm(3) = 4.53,
> nat = 2,
> ntyp = 1,
> ecutwfc = 30.D0 ,
> /
> &electrons
> conv_thr =  1.0d-8
> mixing_beta = 0.7
> /
> ATOMIC_SPECIES
> C   12.0  C.pbe-mt_fhi.UPF
> ATOMIC_POSITIONS crystal
> C  0.00.00.01  1  1
> C  0.3   -0.30.01  1  1
> K_POINTS automatic
>   22 22 1  0 0 0
>
>
> *2) cc.band.in *
>
> &control
> calculation='bands'
> prefix= 'cc'
> pseudo_dir = '/home/pooja/workspace/src/qe/espresso-5.0.2/pseudo/',
> outdir='./out'
> /
> &SYSTEM
> ibrav = 4,
> celldm(1) = 4.608737,
> celldm(3) = 4.53,
> nat = 2,
> ntyp = 1,
> ecutwfc = 30.D0 ,
> nbnd = 12,
> /
> &ELECTRONS
> /
> ATOMIC_SPECIES
> C   12.0  C.pbe-mt_fhi.UPF
> ATOMIC_POSITIONS crystal
> C  0.00.00.01  1  1
> C  0.3   -0.30.01  1  1
> K_POINTS tpiba_b
>  4
>  0.000 0.909 0.0 50
>  0.000 0.000 0.0 50
>  0.787 0.000 0.0 50
>  0.787 0.454 0.0 50
>
>
> *3) cc.bands.in *
>
> &bands
> prefix  = 'cc'
> outdir = 'out'
> filband = 'ccbands.dat'
> lsym=.true.,
> /
>
> *4) cc.plotband.in *
>
> ccbands.dat
> -6.0 10
> ccbands.xmgr
> ccbands.ps
> 6.255
> 1.0 6.255
>
>
>
> I'm unable to find out where it's going wrong, please reply me with
> possible outcome or my mistake.
>
> Thanks in advance.
>
> -Regards,
>  Pooja Dhorge.
>  CSIR-National Chemical Laboratory.
>  India.
> ?
>
> ___
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>



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[Pw_forum] q-point mesh in PHonon

[xirainbow]

Yes, of course.

On Wed, May 14, 2014 at 2:24 AM, Franco Bonaf?  
wrote:
> Dear QE users,
>
> I'm interested in calculating the Raman spectra for a bulk material using
> the PHonon package. I understand that I need to define a q-point mesh that
> generates a Monkhorst-Pack grid to obtain the phonon dispersions.
> I'd like to know how to find the proper values of nq1, nq2, nq3 for this
> purpose. Should it be carried out like a convergence test, until the same
> result is found consistently?
> Thanks to all.
>
> Franco.
>
> --
> Franco P. Bonaf?
> MSc in Chemistry / PhD student
> INFIQC :: CONICET
> Department of Math & Physics
> Facultad de Ciencias Qu?micas
> Universidad Nacional de C?rdoba - Argentina
>
> Phone: +54 351  5353853
> Mobile: +54 9 351 15 5472791
>
> ___
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> http://pwscf.org/mailman/listinfo/pw_forum



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Hui Wang
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[Pw_forum] supercell and k-point

[xirainbow]

Dear David Foster:
  Increase the density of k-mesh from 1*1*1 to l*m*n so as to
make sure that your calculated results converge.

On Sat, Apr 19, 2014 at 3:09 AM, David Foster  
wrote:
> Dear users
>
> I have read in some papers that investigate adsorption of some molecules in 
> the gas phase
>
> on the solid surface, the authors use only gamma point for the supercell of 
> the catalyst (for example
>
> for 3*3*3 supercells). But in another ones, I see that they use some k-point 
> even for supercells.
>
> This subject confuse me. Is there any rule for this? Any help will be 
> appreciated.
>
>
>
> Regards
>
> David Foster
>
> Ph.D. Student of Chemistry
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[Pw_forum] Reg: How to know the mode name and due to which atom it is happening?

[xirainbow]

> omega(  1 -  3) =-16.6  [cm-1]   --> T_1u G_15  G_4- I
> I want to know among T_1u, G_15 and  G_4- , which is belongs to that
> imaginary one?. and This is due to which atom ?.
 It is a three-fold degenerate mode. These three symbols (T_1u
G_15  G_4- I) represent this three-fold degenerate.

>  omega( 1) =  -0.496826 [THz] = -16.572332 [cm-1]
>  ( -0.474725  0.00 -0.149266  0.00  0.011949  0.00 )
>  ( -0.474725  0.00 -0.149266  0.00  0.011949  0.00 )
>  ( -0.478986  0.00 -0.150606  0.00  0.012057  0.00 )
>  ( -0.478907  0.00 -0.150581  0.00  0.012055  0.00 )
   Omega 1?2? 3 are translation modes. Omit it.

[Pw_forum] Reg: How to know the mode name and due to which atom it is happening?

[xirainbow]

Dear
In my calculation, the end of the *.dyn1 file looks like the following content:

" Diagonalizing the dynamical matrix

 q = (0.0   0.0   0.0 )

 **
 omega( 1) =   XX [THz] =  XX [cm-1]
 (  0.142825  0.00  0.142825  0.00  0.323621  0.00 )
 ( -0.142825  0.00 -0.142825  0.00  0.323621  0.00 )
 ( -0.142825  0.00  0.142825  0.00  0.323621  0.00 )
 (  0.142825  0.00 -0.142825  0.00  0.323621  0.00 )
 omega( 2) =   XX [THz] =  XX [cm-1]
 ( -0.226720  0.00  0.264038  0.00 -0.002735  0.00 )
 ( -0.226720  0.00  0.264038  0.00  0.002735  0.00 )
 ( -0.269604  0.00  0.301664  0.00 -0.041874  0.00 )
 ( -0.269604  0.00  0.301664  0.00  0.041874  0.00 )

..."

On Tue, Apr 1, 2014 at 7:49 PM, Peram sreenivasa reddy
 wrote:
> Dear xirainbow,
>
> Thank you very much for your replay.
>
> In that case.dyn1 file also it is giving same only as in the case.ph.out
> file.
>
> Please give me more clarification.
>
> Thanking you.
>
>
> On Tue, Apr 1, 2014 at 3:15 PM, xirainbow  wrote:
>>
>> You can find the answer at the end of  *.dyn* files.
>>
>> On Mon, Mar 31, 2014 at 11:10 PM, Peram sreenivasa reddy
>>  wrote:
>> > Dear Pwscf,
>> >
>> > In my phonon calculations i got one imaginary mode in gamma to X
>> > direction.
>> > I want to know which mode it is? and due to which atom it is happening?
>> >
>> > I checked the case.ph.out file. In this file it is given like below.
>> >
>> > Mode symmetry, O_h (m-3m)  point group:
>> >   omega(  1 -  3) =-16.6  [cm-1]   --> T_1u G_15  G_4- I
>> >   omega(  4 -  6) =122.3  [cm-1]   --> T_1u G_15  G_4- I
>> >   omega(  7 -  9) =145.0  [cm-1]   --> T_2g G_25' G_5+ R
>> >   omega( 10 - 12) =258.5  [cm-1]   --> T_1u G_15  G_4- I
>> >
>> > Here i am attaching the case.agr file
>> >
>> > Here all acoustic modes are given with same frequency. How can know that
>> > particular mode name.
>> >
>> >
>> >  My system is X2YZ type. How can i know this imaginary mode is due to
>> > which
>> > atom. I plotted partial phonon density of states also. But all atoms are
>> > giving same contribution in this acoustic mode region.
>> >
>> >  Thank you in advance.
>> >
>> >
>> >
>> > ___
>> > Pw_forum mailing list
>> > Pw_forum at pwscf.org
>> > http://pwscf.org/mailman/listinfo/pw_forum
>>
>>
>>
>> --
>> 
>> Hui Wang
>> School of physics, Henan University of Science and Technology, Henan,
>> China
>> ___
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>> http://pwscf.org/mailman/listinfo/pw_forum
>
>
>
>
>
>
> ___
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Hui Wang
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[Pw_forum] Reg: How to know the mode name and due to which atom it is happening?

[xirainbow]

You can find the answer at the end of  *.dyn* files.

On Mon, Mar 31, 2014 at 11:10 PM, Peram sreenivasa reddy
 wrote:
> Dear Pwscf,
>
> In my phonon calculations i got one imaginary mode in gamma to X direction.
> I want to know which mode it is? and due to which atom it is happening?
>
> I checked the case.ph.out file. In this file it is given like below.
>
> Mode symmetry, O_h (m-3m)  point group:
>   omega(  1 -  3) =-16.6  [cm-1]   --> T_1u G_15  G_4- I
>   omega(  4 -  6) =122.3  [cm-1]   --> T_1u G_15  G_4- I
>   omega(  7 -  9) =145.0  [cm-1]   --> T_2g G_25' G_5+ R
>   omega( 10 - 12) =258.5  [cm-1]   --> T_1u G_15  G_4- I
>
> Here i am attaching the case.agr file
>
> Here all acoustic modes are given with same frequency. How can know that
> particular mode name.
>
>
>  My system is X2YZ type. How can i know this imaginary mode is due to which
> atom. I plotted partial phonon density of states also. But all atoms are
> giving same contribution in this acoustic mode region.
>
>  Thank you in advance.
>
>
>
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Hui Wang
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[Pw_forum] regarding thermal conductivity

[xirainbow]

Sorry, I do not think so.

On Wed, Mar 26, 2014 at 1:07 AM, kulwinder kaur  
wrote:
>
> hello QE user
>
> how can i find thermal conductivity using quantum espresso code?
>
>
>
>
>
> --
> Regards
> kulwinder kaur
> physics department
> panjab university chandigarh
>
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Hui Wang
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[Pw_forum] curie temperature of double perovskite

[xirainbow]

I do not think you can do it with Q.E.
You can get the exchange parameters with QE and do Monte Carlo
simulation afterward.

On Fri, Mar 21, 2014 at 2:29 AM, Abou Imrane  wrote:
> Dear all,
>
>i want to calculate th curie temperature with QE code  but i dont know
> how i can do it,   please tell me  what i should do.
>
> thanks in advence
>
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[Pw_forum] 3 additional frequencies (6 total) when only displace one atom in the PH.x calculation

[xirainbow]

> The complete ph.x outputs are attached
 You forgot to attach the output files.

> 1. Why are there 3 additional frequencies? Shouldn't there only be 3 (omega 
> 73~75) due to the DoF of one atom?
 Look at the eigenvector and see if the three "-67 cm-1 " are
translational modes.

On Wed, Mar 19, 2014 at 12:57 AM, Kan-Ju Lin  wrote:
> Hi all,
>
> I am using QE 5.0.3.
>
> I am trying to test if a saddle point from the neb.x calculation is a real
> saddle point. I am doing this by looking for the vibrational frequency: If a
> state is a saddle point, it has only one imaginary (negative) frequency. If
> a state is an energy minimum, it has no imaginary frequency.
>
> My system consists of a crystal structure and a helium impurity in it. The
> crystal structures at energy minimum and the saddle point are almost
> identical, only the helium atom is displaced. To facilitate the frequency
> calculation, I used nat_todo = 1 to only allowing the helium to be
> displaced:
>
> phonons of initial state at Gamma
>  &inputph
>   nat_todo = 1
>   tr2_ph=1.0d-14,
>   prefix = "te",
>   epsil=.true.,
>  /
> 0.0 0.0 0.0
> 25
>
> The last line, 25, indicates only the 25th atom (helium) is displaced during
> the ph.x calculation. Because there are 25 atoms total in the system, there
> should be 75 modes. The complete ph.x outputs are attached. The energy
> minimum state has the frequencies:
>
>  omega( 1) =  -2.080553 [THz] = -69.399779 [cm-1]
>  omega( 2) =  -2.080553 [THz] = -69.399779 [cm-1]
>  omega( 3) =  -2.080553 [THz] = -69.399779 [cm-1]
> ..
> ..
>  omega(73) =   4.621913 [THz] = 154.170425 [cm-1]
>  omega(74) =   4.621913 [THz] = 154.170425 [cm-1]
>  omega(75) =   4.621913 [THz] = 154.170425 [cm-1]
>
> with omega(4~72) all equal to zero. For the saddle point one:
>
>  omega( 1) =  -4.316979 [THz] =-143.998928 [cm-1]
>  omega( 2) =  -2.270462 [THz] = -75.734475 [cm-1]
>  omega( 3) =  -2.270462 [THz] = -75.734475 [cm-1]
> ..
> ..
>  omega(73) =   2.168375 [THz] =  72.329209 [cm-1]
>  omega(74) =   9.304582 [THz] = 310.367434 [cm-1]
>  omega(75) =   9.304582 [THz] = 310.367434 [cm-1]
>
>
> My questions are:
> 1. Why are there 3 additional frequencies? Shouldn't there only be 3 (omega
> 73~75) due to the DoF of one atom?
> 2. Why are the three additional frequencies negative? Shouldn't there be one
> negative frequency for the saddle point, and 2 positive frequencies? and no
> negative frequency for the energy minimum?
>
> Please let me know if I understand this incorrectly, or I am missing some
> settings.
>
>
> --
> Kan-Ju Lin, Postdoctoral Associate
> MIT Materials Science and Engineering
> Office 4-053 / kjlin at mit.edu
>
>
>
>
>
> ___
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-- 

Hui Wang
School of physics, Henan University of Science and Technology, Henan, China

[Pw_forum] problem with relaxation and difference between SCF Fermi level and DOS Fermi level

[xirainbow]

> 1. When I do vc-relax calculation to determine the pressure I get the desired 
> pressure but in the last iteration I get a large jump in the pressure (after 
> "begin final coordinate") sometimes in the order of 1000 kbar. Why is it 
> happening and how can I fix it?
  Set the output structure as the input one and relax it again
and agian.


On Thu, Mar 13, 2014 at 3:07 PM, Uri Argaman  wrote:
>
> Dear QE users
> 1. When I do vc-relax calculation to determine the pressure I get the
> desired pressure but in the last iteration I get a large jump in the
> pressure (after "begin final coordinate") sometimes in the order of 1000
> kbar. Why is it happening and how can I fix it?
> 2. I notice that the Fermi level in the SCF file is not the same as the
> Fermi level in the DOS file. Why is that?
> Thank you very much
>
> Uri Argaman
> Ben-Gurion University
> Israel
>
>
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Hui Wang
School of physics, Henan University of Science and Technology, Henan, China

[Pw_forum] choosing k-point in slab calculations

[xirainbow]

Dear David,
  I think you confused some concept about kpoints.

>  band structure for the plane parallel to the surface but in the middle point 
> of the vacuum
Band structure is in the reciprocal space. Vacuum
is in the real space. You can get the electron density but not the
band structure in the real space.

On Mon, Mar 10, 2014 at 3:19 AM, David Foster  
wrote:
> Dear Users
>
> Suppose, we have constructed a metallic surface and a vacuum slab with some 
> thickness.
>
> Normally, these super-cells have no symmetry. My main question is that how we 
> should
>
> choose the k-point? Only in the surface or we can choose some points in the 
> inner layers
>
> or even vacuum near to the surface?
>
>
>
> PS: I have calculated band structure for the plane parallel to the surface 
> but in the middle
>
> point of the vacuum (far from the surface). I expected that I didn't get any 
> band graphs; however,
>
> I got some. Can anybody tell me why?
>
>
>
> Regards
>
> David Foster
>
> Ph.D. Student of Chemistry
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-- 

Hui Wang
School of physics, Henan University of Science and Technology, Henan, China

[Pw_forum] STO Structure breaking - reg.,

[xirainbow]

>  nat = 6,
   If you want to deal with H doping into STO, your model is
wrong. You must create a large STO supercell and then add only one H
to this large suppercell.
   If you want to calculate a new crystal: HSrTiO3, nat = 6 is right.

>  ecutwfc = 25 ,
   In my point of view, it is two low for NCPP.

> K_POINTS automatic
   In my point of view, it is two low for your structure. I
usually use 8*8*8 for this condition.

[Pw_forum] unit of phonon dos

[xirainbow]

Dear Gao:

> The calculated phonon dos of 6-atom cell by matdyn.x is exactly two times as
> large as that of 3-atom cell.
> I guess that the phonon dos is not normalised to 3*nat, am I right?

If  "the calculated phonon dos of 6-atom cell is exactly two times as
 large as that of 3-atom cell.", the "phonon dos is normalised to 3*nat".

[Pw_forum] Magnetism

[xirainbow]

Try adding  "Emin=XXX,  Emax=XXX" in your pdos.in.


On Tue, Feb 25, 2014 at 7:27 PM, Winfred Mulwa  
wrote:
> Dear QE users,
> I want to do a PDOS calculation on a TiO2 doped with Cr which
> is magnetic. Attached is my input file. I have succeeded in doing the scf,
> nscf, dos but when i do the PDOS, the calculation fails with an error
> from davcio : error # 10
> error while reading from file.
> Please tell me what the problem is.
> Regards.
> Mulwa Winfred.
> D Phil Student, Computational Material Science Group,
> University of Eldoret,
> Eldoret, Kenya.
>
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-- 

Hui Wang
School of physics, Henan University of Science and Technology, Henan, China

[Pw_forum] phonon calculation

[xirainbow]

Yes, of course.

On Fri, Feb 21, 2014 at 7:52 PM, yelena  wrote:
> Hello!
>
> I was using ph.x to calculate phonons at gamma point. I got dynamical
> matrix for gamma and atomic displacement, mode symmetry...
> I was wondering if this all is possible to get for any other point (K,
> M...)?
> Best,
> Jelena Pesic
> PhD Student,
> Center for Solid State Physic and New Materials,
> Institute of Physics, Belgrade, Serbia
> ___
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-- 

Hui Wang
School of physics, Henan University of Science and Technology, Henan, China

[Pw_forum] regarding born-effective charge

[xirainbow]

You can add "  epsil=.true.," in Gamma-point phonon calculation. And
then the BECs will be calculated automatically with DFPT.

On Thu, Feb 20, 2014 at 11:49 AM,   wrote:
> --
> --
>
> Respected QE users,
> I tried to perform Born-effective charge calculation
> according to the procedure given in example10 of
> Example Directory. I first did scf calculation by
> displacing 0.05Angstrom one of the atom along x-axis
> and then did nscf calculation with options
> lberry=.true.,gdr=1 and nppstr=70.
>
> but i am getting NAN value, here is the output
>
>   VALUES OF POLARIZATION
>  ~~
>
> The calculation of phases done along the direction of vector 1
> of the reciprocal lattice gives the following contribution to
> the polarization vector (in different units, and being Omega
> the volume of the unit cell):
>
>P = NaN  (mod   8.2766587)  (e/Omega).bohr
>
>P = NaN  (mod   0.0033970)  e/bohr^2
>
>P = NaN  (mod   0.1942150)  C/m^2
>
> The polarization direction is:  ( 1.0 , 0.0 , -.0 )
>
>  System has 1.32eV band gap also. could you please suggest me how
> to get the correct value of Born-effective charge.
>
> Regards
> Himanshu
> IOPB
>
>
>
>
>
> ___
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-- 

Hui Wang
School of physics, Henan University of Science and Technology, Henan, China

[Pw_forum] [EXTERNAL] Re: How to reuse cell geometry for successive straining of a lattice

[xirainbow]

Dear Jon,
I hope this is what you want :)
http://blog.sina.com.cn/s/blog_5f15ead20101r5uv.html

On Fri, Jan 24, 2014 at 9:08 AM, Zimmerman, Jonathan A
 wrote:
> Thank you Axel, I will give your first suggestion a try and let you know
> if I need the elaborate option.
>
> Many thanks and regards,
>
> Jon
> --
> Jonathan A. Zimmerman
> Principal Member of Technical Staff
> Mechanics of Materials Department
> Sandia National Laboratories
> P.O. Box 969 - MS 9957
> Livermore, CA 94551
>
> Tel: (925) 294-2437 or (800) 4SANDIA x4-2437
> Fax: (925) 294-2355
> E-mail: jzimmer at sandia.gov
> --
>
>
>
>
>
> On 1/23/14 2:14 PM, "Axel Kohlmeyer"  wrote:
>
>>On Wed, Jan 22, 2014 at 9:06 PM, Zimmerman, Jonathan A
>> wrote:
>>> Hi Pw_forum folks,
>>
>>hi jon,
>>
>>> I'm new to Quantum Espresso, but I have checked the archives and I don't
>>> think this question has been asked (at least not this way). Here goes:
>>>
>>> I'd like to perform a series of vc-relax calculations on a crystal
>>>lattice
>>> such that each time I increase the amount of applied strain in a given
>>> direction (via the CELL_PARAMETERS), from one calculation to the next I
>>> reuse the other, unconstrained CELL_PARAMETERS and the ATOMIC_POSITIONS.
>>> This way, my Poisson contraction and non-uniform relaxation of the
>>>atoms is
>>> done gently, rather than restarting each calculation with the same
>>> 'unrelaxed' ATOMIC_POSITIONS. I'm hoping that a few of you have done
>>> something similar and have a script or suggestions for carrying-over the
>>> CELL_PARAMETERS (those I'm not fixing) and ATOMIC_POSITIONS from one
>>> calculation to the next. If so, please respond.
>>
>>since nobody else responded to your question here are a few thoughts on
>>that:
>>
>>what you want to do should be easily doable with a little bit of
>>scripting. i suggest you have a look at the pwo2xsf.sh script that can
>>be used to extract coordinates from a QE run into an .xsf file, which
>>contains coordinates and cell vectors. similarly, there is xsf2pwi.sh,
>>that would convert a set of .xsf coordinates to a format suitable for
>>input of pw.x. if you write a little script to process a given input
>>file template, then you can combine these two scripts with your script
>>and do the processing as you intend to do.
>>
>>it might also be possible to combine this.
>>
>>another, more elaborate, option would be to adopt the new "COUPLE"
>>interface that allows to interface pw.x in a (superficially) similar
>>fashion as you know it from LAMMPS. so you could make it run a
>>repeated relaxation output the final coordinates, modify, and
>>continue. this code is only available through the svn currently. but
>>if you want to go this route, please contact me off-list and i'd be
>>more than happy to collaborate with you to write a little "driver" for
>>your needs.
>>
>>best regards from philly,
>>
>>axel.
>>
>>>
>>> Thanks!
>>>
>>> Jon Zimmerman
>>> --
>>> Jonathan A. Zimmerman
>>> Sandia National Laboratories
>>> E-mail: jzimmer at sandia.gov
>>> --
>>>
>>>
>>> ___
>>> Pw_forum mailing list
>>> Pw_forum at pwscf.org
>>> http://pwscf.org/mailman/listinfo/pw_forum
>>
>>
>>
>>--
>>Dr. Axel Kohlmeyer  akohlmey at gmail.com  http://goo.gl/1wk0
>>College of Science & Technology, Temple University, Philadelphia PA, USA
>>International Centre for Theoretical Physics, Trieste. Italy.
>>___
>>Pw_forum mailing list
>>Pw_forum at pwscf.org
>>http://pwscf.org/mailman/listinfo/pw_forum
>
>
> ___
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> http://pwscf.org/mailman/listinfo/pw_forum



-- 

Hui Wang
School of physics, Henan University of Science and Technology, Henan, China

[Pw_forum] SPIN POLARIZATION CALCULATIONS

[xirainbow]

Dear Jamil,

> For a spin polarization calculations, for a molecular system,is that we must 
> take into account all the atoms considered in our system with 
> starting_magnetization or just take only one? In the second case, which atom 
> we must choose with starting_magnetization?

  It is up to you. If you do not know, no one else know the answer.
  In my experience in crystal calculations, the final
magnetization depends on the initial value. Starting with different
starting_magnetization, I can get para, ferro, or
antiferro-magnetization after scf calculations.

On Fri, Jan 24, 2014 at 5:49 PM, MISSAOUI Jamil
 wrote:
> Hi,
> I found problems with starting_magnetization, PLEASE, I want answers for
> these questions.
> 1 / For a spin polarization calculations, for a molecular system, is that we
> must take into account all the atoms considered in our system with
> starting_magnetization or just take only one? In the second case, which atom
> we must choose with starting_magnetization?
> 2 /Which value of starting_magnetization we fix  (between -1 and 1) in the
> case of spin polarization calculations, or we need a convergence
> calculations to fix it.?
> Thanks.
> Jamil.
>
> ___
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> http://pwscf.org/mailman/listinfo/pw_forum



-- 

Hui Wang
School of physics, Henan University of Science and Technology, Henan, China

[Pw_forum] (no subject)

[xirainbow]

Yes, of course:)
For the same crystal structure, starting with different initial
magnetizations, you can obtain paramagnetic, ferromagnetic or even
antiferromagnetic results.

On Wed, Jan 22, 2014 at 11:11 PM, MISSAOUI Jamil
 wrote:
> Hi,
> I want to know is that in a magnetic systems if we change the
> starting_magnetization of atoms will effect on the magnetic properties of
> our system or not.
> because i think that's for example if we have the system (XY), so it will be
> the same to consider starting_magnetization(1) or starting_magnetization(2),
> but in our calculations a get a different results.
> Thanks.
>
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-- 

Hui Wang
School of physics, Henan University of Science and Technology, Henan, China

[Pw_forum] ibrav for orthorhombic space group

[xirainbow]

Dear David Foster:
  Orthorhombic P = composed of P.
  Orthorhombic base-centered(bco) = C and A.
  Orthorhombic face-centered = F
  Orthorhombic body-centered  = I.
  You can find more information at here if you can read Chinese.
http://blog.sina.com.cn/s/blog_5f15ead20100wmjl.html


On Fri, Jan 10, 2014 at 2:41 PM, David Foster  
wrote:
> Hi everybody
>
> Orthorhombic space group (Numbered from 16 to 74) has five different kinds of 
> classes starting
>
> with "P" "C"  "A"  "F"  "I".
>
> P such as 56.Pccnor  57.Pbcm
>
> C such as 36.Cmc21  or   37.Ccc2
>
> A such as 40.Ama2   or41.Aba2
>
> F such as 42.Fmm2   or 43.Fdd2
>
> I such as 44.Imm2  or45.Iba2
>
> My question is about ibrav assignment to above space groups.
>
>
> in manual we have:
>
> 
>  8  Orthorhombic P  celldm(2)=b/a
>  celldm(3)=c/a
>   v1 = (a,0,0),  v2 = (0,b,0), v3 = (0,0,c)
>
>   9  Orthorhombic base-centered(bco) celldm(2)=b/a
>  celldm(3)=c/a
>   v1 = (a/2, b/2,0),  v2 = (-a/2,b/2,0),  v3 = (0,0,c)
>  -9  as 9, alternate description
>   v1 = (a/2,-b/2,0),  v2 = (a/2,-b/2,0),  v3 = (0,0,c)
>
>  10  Orthorhombic face-centered  celldm(2)=b/a
>  celldm(3)=c/a
>   v1 = (a/2,0,c/2),  v2 = (a/2,b/2,0),  v3 = (0,b/2,c/2)
>
>  11  Orthorhombic body-centered  celldm(2)=b/a
>  celldm(3)=c/a
>   v1=(a/2,b/2,c/2),  v2=(-a/2,b/2,c/2),  v3=(-a/2,-b/2,c/2)
> ===
>
> so, it is clear that ibrav for "P" is 8, for "I" is 11 (I am not sure), for 
> "F" is 10.
>
> What about "C" and "A"?
>
>
>
>
> Regards
>
> David Foster
>
> Ph.D. Student of Chemistry
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School of physics, Henan University of Science and Technology, Henan, China

[Pw_forum] K points: phonon dispersion

[xirainbow]

I hope it works:)


 &input
asr='simple',
dos=.true.
amass(1)=,
amass(2)=XXX,
flfrc='AlN.fc'
fldos='AlN.ph.dos',
flfrq='AlN.ph.dos.freq'
flvec='AlN.ph.dos.modes'
nk1=12,nk2=12,nk3=12



On Wed, Dec 25, 2013 at 6:50 PM, ramzi alaya  wrote:
>
> Hi Quantum Espresso users
>
> I am trying to calculate the phonon dispersion of Wurtzite AlN. Could
> someone send me please the input script 'matdyn. in'
>
> Kindest Regards,
>
>
> Alaya Ramzi
> Cit? Erriadh 6072 Gab?s- Tunisie
> LAPHYMNE
> ramzialaya at hotmail.fr
>
>
>
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> http://pwscf.org/mailman/listinfo/pw_forum



-- 

Hui Wang
School of physics, Henan University of Science and Technology, Henan, China

[Pw_forum] ELASTIC code with Quantum Espresso

[xirainbow]

http://blog.sina.com.cn/s/blog_5f15ead20101mndt.html

On Tue, Nov 26, 2013 at 9:29 AM, victoir victoir
 wrote:
> Hellos all,
>
> I am interested by the mechanical properties (elastic constant) and I want
> to work with the ELASTIC code.
>
> I usually work with Quantum Espresso, but now I don?t know how to work with
> both at the same time and also i don?t know the installation method and the
> extension of file input and commands must type exactly in the terminal;
>
> please help me to understand how to do the calculation;
>
> Cordially
>
>
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-- 

Hui Wang
School of physics, Henan University of Science and Technology, Henan, China

[Pw_forum] not converge after 100 itration

[xirainbow]

Dear:
   Suggestions:
   0. see your structure in Xcrysden.
   1. increase ecutwfc  to 50.
   2. set "K_POINTS " as "1 1 1 0 0 0".

  BTW: you system contains 32 atoms. It may be normal to stop
after 150 or 200 iterations.

On Mon, Nov 25, 2013 at 3:03 AM, ehsan targholi  wrote:
> dear all pw users,
> my relax calculation is not converge after 100 iteration . please help me to
> find problem in input.
> my input is :
>
>
> &CONTROL
>   calculation = "relax",
>   prefix   = "test",
>   pseudo_dir  = "/home/ehsan/espresso-5.0/upf_files/",
>   outdir  = "/home/ehsan/espresso-5.0/tmp/",
> /
> &SYSTEM
>   ibrav = 0,
>   nat   = 32,
>   ntyp  = 1,
>   ecutwfc   = 22.D0,
>   ecutrho   = 240.D0,
> /
> &ELECTRONS
>   conv_thr= 1.D-6,
>   mixing_beta = 0.7D0,
> /
> &IONS
> /
> CELL_PARAMETERS {angstrom}
>  9.838048590.0.
>  4.919024298.52000.
>  0.0.10.000
> ATOMIC_SPECIES
> C  12.0  C.pw91-van_ak.UPF
> ATOMIC_POSITIONS {angstrom}
>  C3.074390181.7750   -0.
>  C0.614878040.3550   -0.
>  C5.533902331.7750   -0.
>  C7.993414481.7750   -0.
>  C10.45292662   1.7750   -0.
>  C3.074390180.3550   -0.
>  C5.533902330.3550   -0.
>  C7.993414480.3550   -0.
>  C4.304146263.9050   -0.
>  C5.533902336.0350   -0.
>  C6.763658408.1650   -0.
>  C1.844634112.4850   -0.
>  C3.074390184.6150   -0.
>  C4.304146266.7450   -0.
>  C6.763658403.9050   -0.
>  C7.993414486.0350   -0.
>  C9.223170558.1650   -0.
>  C9.223170553.9050   -0.
>  C10.45292662   6.0350   -0.
>  C11.68268270   8.1650   -0.
>  C11.68268270   3.9050   -0.
>  C12.91243877   6.0350   -0.
>  C14.14219484   8.1650   -0.
>  C4.304146262.4850   -0.
>  C5.533902334.6150   -0.
>  C6.763658406.7450   -0.
>  C6.763658402.4850   -0.
>  C7.993414484.6150   -0.
>  C9.223170556.7450   -0.
>  C9.223170552.4850   -0.
>  C10.45292662   4.6150   -0.
>  C11.68268270   6.7450   -0.
> K_POINTS {automatic}
> 12 12 1 0 0 0
>
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-- 

Hui Wang
School of physics, Henan University of Science and Technology, Henan, China

[Pw_forum] elastic constant of graphene through the ELASTIC code and QE

[xirainbow]

Dear victoir:
 First of all, it is not a right place to ask for help of
ELASTC code. You could try to ask it in the ELASTIC forum.
 Second, you may find some help information at here :
http://blog.sina.com.cn/s/blog_5f15ead20101mndt.html


On Sat, Nov 2, 2013 at 4:37 AM, victoir victoir
 wrote:
> Dear all
>
>  Please help me
>
> I want the calculated elastic constant of graphene through the ELASTIC code,
> I installe QUANTUM ESPRESSO.
>
> What step I need to do to calculate the elastic constant with QUANTUM
> ESPRESSO?
>
> Sincerely
>
>
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-- 

Hui Wang
School of physics, Henan University of Science and Technology, Henan, China

[Pw_forum] probleme with pdos

[xirainbow]

Dear H.ZAARI:

> is what I have to subtract the value of the Fermi level for this level to  
> zero.?
If you just want to do a simple pdos figure, yes.

> in the attached file you can find the file. in for the partial density it 
> gives me the error in namelist .  can you help me please
Rewrite pdos.in as this and have a try.
&projwfc
outdir='/home/halima/quatumespre/Nouveau dossier/GaN/GaN'
prefix='Guallium'
Emin=5.0,Emax=25.0, deltaE=0.1

[Pw_forum] Magnetic Field

[xirainbow]

Dear Farzad Shirazian:
  I do not think QE can apply magnetic field to a system.

On Thu, Jun 27, 2013 at 5:42 AM, Farzad Shirazian
 wrote:
> Dear all,
> Is it possible to apply a magnetic field of a specific value to a system
> with QE? If it is not added to the package yet, is there a trick to study a
> system under a magnetic field?
> Any help would be greatly appreciated.
>
> Best Regards,
> Farzad Shirazian
> Sharif University of Technology
>
>
>
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Hui Wang
School of physics, Fudan University, Shanghai, China

[Pw_forum] What does total energy contain?

[xirainbow]

Dear Wu:
In C.pz-hgh.UPF, you can find :
 total_psenergy="0.000E+000"
pseudo_energy="-1.002687685316557E+000"
pseudo_energy="-3.982653648547184E-001"

In C.pw-mt_fhi.UPF, you can find :
total_psenergy="0.000E+000"
pseudo_energy="0.000E+000"
pseudo_energy="0.000E+000"




On Thu, Jun 20, 2013 at 12:28 AM, Yantao Wu  wrote:
> So it doesn't add the pre-calculated core electron energy into the total
> energy in the end?
>
>
> On Wed, Jun 19, 2013 at 12:04 AM, xirainbow  wrote:
>>
>> Dear Wu:
>>  I think the scf total energy contains Madelung energy.
>>  I do not think pseudopotential takes the core electron
>> energy into account.
>>
>> On Wed, Jun 19, 2013 at 2:20 AM, Yantao Wu  wrote:
>> > Dear QE,
>> >
>> > In a scf calculation, I'm wondering whether the output total energy
>> > contains
>> > the energy of the core electrons. Does the use of pseudopotential mean
>> > that
>> > only the energy due to the valence electrons is included in total
>> > energy?
>> > Also I assume that Madelung energy of the system is included in total
>> > energy, right?
>> >
>> > Thanks,
>> > Yantao Wu
>> >
>> > ___
>> > Pw_forum mailing list
>> > Pw_forum at pwscf.org
>> > http://pwscf.org/mailman/listinfo/pw_forum
>>
>>
>>
>> --
>> 
>> Hui Wang
>> School of physics, Fudan University, Shanghai, China
>> ___
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>> http://pwscf.org/mailman/listinfo/pw_forum
>
>
>
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Hui Wang
School of physics, Fudan University, Shanghai, China

[Pw_forum] What does total energy contain?

[xirainbow]

Dear Wu:
 I think the scf total energy contains Madelung energy.
 I do not think pseudopotential takes the core electron
energy into account.

On Wed, Jun 19, 2013 at 2:20 AM, Yantao Wu  wrote:
> Dear QE,
>
> In a scf calculation, I'm wondering whether the output total energy contains
> the energy of the core electrons. Does the use of pseudopotential mean that
> only the energy due to the valence electrons is included in total energy?
> Also I assume that Madelung energy of the system is included in total
> energy, right?
>
> Thanks,
> Yantao Wu
>
> ___
> Pw_forum mailing list
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Hui Wang
School of physics, Fudan University, Shanghai, China

[Pw_forum] Fwd: Raman result wrong, intensity at 0.0 cm-1 is

[xirainbow]

Dear Xue  Yong:
 The frequencies of the first six modes are zero. However, I
did not find translation modes in the eigenvector of the first six
modes. I guess the non-zero Raman intensity is related with it.

On Tue, Jun 18, 2013 at 4:30 AM, Yong Xue  wrote:
>
> Dear xirainbow (nkxirainbow at gmail.com)
>
> Sorry for the late reply as I had some problem with my account several days
> ago.
> Here are the mode.
> [Molden Format]
> [FREQ]
> 0.00
> 0.00
> 0.00
> 0.00
> 0.00
> 0.00
>   634.63
>   634.63
>   634.63
>   819.64
>   819.64
>  2524.20
>  2546.54
>  2546.54
>  2546.54
> [FR-COORD]
>Si  0.00.00.0
>H   1.542021.542021.54202
>H  -1.54202   -1.542021.54202
>H  -1.542021.54202   -1.54202
>H   1.54202   -1.54202   -1.54202
> [FR-NORM-COORD]
>  vibration 1
>0.00078   0.00332   0.06405
>   -0.25495   0.23274   0.09036
>   -0.26389   0.24168   0.03774
>0.26545  -0.22610  -0.43004
>0.25651  -0.23504   0.55814
>  vibration 2
>0.19059   0.04544  -0.10557
>0.42670  -0.21755  -0.07869
>   -0.16975   0.37891  -0.13246
>0.55094   0.30844  -0.20293
>   -0.04551  -0.28802  -0.00822
>  vibration 3
>0.13959  -0.28587   0.14499
>0.11628  -0.53070   0.41314
>0.04587  -0.46029  -0.12315
>0.23331  -0.04104   0.29610
>0.16290  -0.11145  -0.00612
>  vibration 4
>   -0.14867  -0.20599  -0.24206
>   -0.17210  -0.20740  -0.21722
>   -0.40949   0.02999  -0.26690
>0.11215  -0.20458  -0.50147
>   -0.12525  -0.44197   0.01734
>  vibration 5
>0.09114  -0.02012  -0.06924
>   -0.21741   0.40640  -0.18721
>0.43407  -0.24508   0.04874
>   -0.25178  -0.44664  -0.15283
>0.39970   0.20483   0.01436
>  vibration 6
>   -0.00483   0.03661  -0.03056
>   -0.32588  -0.12775   0.45485
>   -0.17438  -0.27925  -0.51598
>0.16472   0.20098  -0.03575
>0.31622   0.35247  -0.02538
>  vibration 7
>0.01862  -0.03413   0.04143
>   -0.10205   0.46512  -0.34732
>   -0.41581   0.15135  -0.22988
>0.15640   0.01034  -0.08886
>   -0.15736   0.32410  -0.48833
>  vibration 8
>0.00106  -0.04361  -0.03640
>   -0.31038   0.16997   0.09246
>   -0.03471   0.44564   0.41466
>0.01989   0.43758   0.42272
>0.29556   0.16191   0.08440
>  vibration 9
>   -0.05367  -0.01271   0.01365
>0.37742  -0.06301  -0.34643
>0.27402  -0.16641   0.15622
>0.47364   0.24002  -0.25021
>0.37024   0.34342   0.06000
>  vibration10
>0.0   0.0   0.0
>   -0.31074  -0.07393   0.38467
>0.31074   0.07393   0.38467
>0.31074  -0.07393  -0.38467
>   -0.31074   0.07393  -0.38467
>  vibration11
>0.0   0.0   0.0
>0.26478  -0.40150   0.13672
>   -0.26478   0.40150   0.13672
>   -0.26478  -0.40150  -0.13672
>0.26478   0.40150  -0.13672
>  vibration12
>0.0   0.0   0.0
>0.28868   0.28868   0.28868
>   -0.28868  -0.28868   0.28868
>   -0.28868   0.28868  -0.28868
>0.28868  -0.28868  -0.28868
>  vibration13
>   -0.01650   0.02841   0.02284
>   -0.26053  -0.24431  -0.24632
>0.07421   0.09043  -0.07192
>0.15573  -0.15143   0.16994
>0.49047  -0.48617  -0.48818
>  vibration14
>   -0.01068  -0.02774   0.02678
>0.08143   0.07527   0.09496
>0.47391   0.46775  -0.46809
>   -0.32512   0.31125  -0.31159
>0.06736  -0.08124  -0.06154
>  vibration15
>0.03485   0.00495   0.01903
>   -0.41844  -0.42924  -0.42416
>   -0.13965  -0.15045   0.15910
>   -0.34589   0.36027  -0.35161
>   -0.06710   0.08148   0.08656
>
>  Date: Thu, 23 May 2013 21:39:24 +0800
> From: xirainbow 
> Subject: Re: [Pw_forum] Raman result wrong, intensity at 0.0 cm-1 is
> not zero.
> To: PWSCF Forum 
> Message-ID:
>  mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> Dear Yong:
> Can you give the eigenvectors of  the translation and
> rotation modes ?
>
> On Thu, May 23, 2013 at 2:31 AM, Yong Xue  wrote:
>
>> Dear All
>>
>> I have calculated both raman and IR spectrum for SiH4 as given in the
>> handson tutorial as well as my own system for my own system composed by C
>> and O atoms only.
>>  Here is the input for nm
>>
>> Normal modes for SiH4
>>
>> &inputph
>>
>> tr2_ph=1.0d-14,
>>
>> prefix='sih4',
>>
>> amass(1)=28.086,
>>
>> amass(2)=1.008,
>

[Pw_forum] CNT unit cell vectors

[xirainbow]

> what is the difference between scf and relax calculations since all DFT are 
> self consistent?
 In relax calculation, atoms move to decrease the energy.
 In scf, atoms are fixed.

> I found carbon nanotubes input files using ibrav=6 and others using ibrav=8, 
> so how can I which one I should use?
As long as the distance between neighboring CNT is big
enough, you can choose any one.




On Sun, Jun 16, 2013 at 2:00 AM, Mahmoud Hammouri  wrote:
> Thank you Wang for you answer. I found carbon nanotubes input files using
> ibrav=6 and others using ibrav=8, so how can I which one I should use?
> Another question: what is the difference between scf and relax calculations
> since all DFT are self consistent?
>
> Mahmoud
>
> On Jun 15, 2013, at 4:03, "pw_forum-request at pwscf.org"
>  wrote:
>
> Wang
>
>
> ___
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-- 

Hui Wang
School of physics, Fudan University, Shanghai, China

[Pw_forum] CNT unit cell vectors

[xirainbow]

Dear Mahmoud Hammouri:
   For Tetragonal P, "a" must be equal to "b". Therefore, it
is forbidden to set "b" as an individual variable.
   For an isolated CNT, you can set "a" arbitrarily. But the
condition is not true for "c" ("c" is along the axis of CNT ). The
length of "c" of CNT changes much with the chiral angle of CNT.


On Fri, Jun 14, 2013 at 5:22 PM, Mahmoud Hammouri  wrote:
> Hi all,
> I have problem for defining the lattice vectors of carbon nanotubes, I saw
> some examples for zigzag CNTs and they are using ibrav =6 with celldm(1)=31
> and celldm(3)= 0.25 and in another file celldm(3)=0.1704 I'm really wonder
> why they did not define celldm(2)? Now, for more than one unit cell how
> celldm(3) would change.
> In the descriptions of the pw.x input file, for Tetragonal P (st):
>  celldm(3)=c/a and since c=1.42 and a=4.26 then celldm(3)=0.333 not 0.25 or
> 0.17 as others said!!!
>
>
> Regards
>
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-- 

Hui Wang
School of physics, Fudan University, Shanghai, China

[Pw_forum] band structure, can't I use hybrid functional?

[xirainbow]

Dear Davide:
  I guess so.
  In LDA and GGA functionals, the Hamiltonian is only
related with charge density. Therefore, band structure can be
calculated with nscf.
  However, in hybrid functional, the Hamiltonian is not
only related with charge density but also with wavefuncitons.
Therefore, band structure must be calculated with scf, instead of
nscf.

On Sat, Jun 8, 2013 at 8:15 PM, Davide Tiana  wrote:
> Dear Hui Wang
> thanks for answering.
> I know how to it with vasp, so in QE I had to do exactly the same
> procedure as in vasp?
>
> Cheers,
> Davide
>>
>> --
>>
>> Message: 5
>> Date: Sat, 8 Jun 2013 17:09:31 +0800
>> From: xirainbow 
>> Subject: Re: [Pw_forum] band structure, can't I use hybrid functional?
>> To: PWSCF Forum 
>> Message-ID:
>>   
>> Content-Type: text/plain; charset=ISO-8859-1
>>
>> Dear  Davide:
>> I have a tip to do band calculation for band with HSE
>> hybrid functional.
>> 1:do scf calculation on a regular k-mesh (for example
>> 4*4*4) and save charge density and wavefunction.
>> 2: write the k mesh by hand:  Add additional k points to
>> the regular k-mesh and set the weight of these k point to zero.
>> 3: do scf calculation again.
>>
>> You can find more information at here:
>> http://blog.sina.com.cn/s/blog_5f15ead20100wpqr.html
>> It is HSE band calculation procedure using VASP.
>>
>>
>>
>> --
>> 
>> Hui Wang
>> School of physics, Fudan University, Shanghai, China
>>
>>
>
>
>
> ___
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-- 

Hui Wang
School of physics, Fudan University, Shanghai, China

[Pw_forum] band structure, can't I use hybrid functional?

[xirainbow]

Dear  Davide:
I have a tip to do band calculation for band with HSE
hybrid functional.
1:do scf calculation on a regular k-mesh (for example
4*4*4) and save charge density and wavefunction.
2: write the k mesh by hand:  Add additional k points to
the regular k-mesh and set the weight of these k point to zero.
3: do scf calculation again.

You can find more information at here:
http://blog.sina.com.cn/s/blog_5f15ead20100wpqr.html
It is HSE band calculation procedure using VASP.

On Sat, Jun 8, 2013 at 3:11 PM, Davide Tiana  wrote:
> Hello,
> I need to perform an hybrid calculation on a 1D polymer. I managed to
> make an optimisation but when I run the bands calc, pw complains
> saying it can't perform a non-scf calc using hybrid.
> is there any way to avoid this? I mean, is there a chance to have an
> hybrid band strucutre?
>
> Cheers,
> Davide
>
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Hui Wang
School of physics, Fudan University, Shanghai, China

[Pw_forum] vc-relax

[xirainbow]

Dear Muhammad Zafar:
   grep "End final coordinates"  *.out

On Thu, Jun 6, 2013 at 5:44 PM, zafar rasheed wrote:

> Dear All
>
> I perform 'vc-relax ' calculation of 8 atoms zinc blende structure at
> fixed lattice parameter.
> after calculation I get new positions and cell volume.
>
> My question is that which lattice parameter should I use for the next
> calculations.
>
> Actual given in input of vc-relax or derive from the relaxed structure
> (from last volume)
>
> Muhammad Zafar
> PhD Scholar
> Department of Physics
> The Islamia University of Bahawalpur,Pakistan
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School of physics, Fudan University, Shanghai, China
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[Pw_forum] Real displacements from the complex eigenvectors

[xirainbow]

Dear Alexandr Fonari:
  I think the real displacement at q!=0  is : displacement =
real(eigenvector*exp(i*k*r-omega*t)). real() means the real part,
omega is frequency, t is time, r is the equilibrium position of atoms.


On Thu, Jun 6, 2013 at 2:12 AM, A F  wrote:
> Hello pw_forum,
>
> I have a question with regard to the normal modes at non G-point (q/=0).
> As discussed previously [1], phase is random.
> Thus my question is, how one can obtain displacements in real space from
> those complex displacements?
>
>
> 1. http://qe-forge.org/pipermail/pw_forum/2006-August/079408.html
>
> = = = = = = = = = =
> Alexandr Fonari,
> graduate student,
> Georgia Institute of Technology.
>
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Hui Wang
School of physics, Fudan University, Shanghai, China

[Pw_forum] phonon calculation

[xirainbow]

Dear Banafshe Noori :

> can i use of press_conv_thr   for a relax of phonon calculation?
What is "relax of phonon calculation"? You can even do
phonon with experimental crystal lattices and atomic positions without
any relaxation.

> and why the stress on my system is too high?(-40kbar)
   Take the output structure of pw.x as an input and relax it
again and again.

> What parameters do I need to be changed to reduce stress?
Reduce press_conv_thr.

On Sun, Jun 2, 2013 at 2:36 PM, Banafshe Noori  wrote:
> Dear Xirainbow
>
> thank alot for your respond.
>
> I search in the input file of pwscf and saw that the is applied for a
> vc-relax calculation.
> can i use of press_conv_thr   for a relax of phonon calculation?
> and why the stress on my system is too high?(-40kbar)
> What parameters do I need to be changed to reduce stress?
>
>
>
>
>
> Dear Banafshe Noori :
> press_conv_thr is the parameter to control the final stress.
> The default value for press_conv_thr is  0.5D0 Kbar, which
> is good enough for most condition.
>
> On Sat, Jun 1, 2013 at 11:45 PM, Banafshe Noori  
> wrote:
>> Dear all
>>
>> I want to calculate phonon frequency. I did a relax for my system(carbon
>> nanotube) and saw that  the stress (Kbar) for this system is around
>> (-40Kbar). How can i decrease the stress on my system, and for an
>> acceptable
>> magnitude of ferquencey,  how much be the stress on system.?
>>
>
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School of physics, Fudan University, Shanghai, China

[Pw_forum] phonon calculation

[xirainbow]

Dear Banafshe Noori :
press_conv_thr is the parameter to control the final stress.
The default value for press_conv_thr is  0.5D0 Kbar, which
is good enough for most condition.

On Sat, Jun 1, 2013 at 11:45 PM, Banafshe Noori  wrote:
> Dear all
>
> I want to calculate phonon frequency. I did a relax for my system(carbon
> nanotube) and saw that  the stress (Kbar) for this system is around
> (-40Kbar). How can i decrease the stress on my system, and for an acceptable
> magnitude of ferquencey,  how much be the stress on system.?
>
> ___
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Hui Wang
School of physics, Fudan University, Shanghai, China

[Pw_forum] What is the function of "drho_e" file?

[xirainbow]

Dear all:

   When I do ph.x calculation, there are "drho_e1, drho_e2,
drho_e3" files in the running directory.
   The name of "drho_e" files do not change with prefix of the
phonon.input file.

   Are "drho_e1, drho_e2, drho_e3" files  are used by ph.x or
by dynmat.x or other pp?

   Can I run many ph.x in the same directory at the same time  ?

   Thank you in advance :)

-- 

Hui Wang
School of physics, Fudan University, Shanghai, China

[Pw_forum] "Raman activities" do not converge

[xirainbow]

Dear Lorenzo Paulatto:
  Thank you very much for your suggestion:)

> Compare the output of pw.x at different cutoffs to be sure, my bet is
> that at that specific value of ecutwfc some symmetry operations are
> incompatibles with the FFT grid.
 The "FFT vs Symmetry" condition really happens.
  However, it has no relation with "Ramman activity". See
the following table.

Using "C.pw-mt_fhi.UPF" :
ecutwfc(Ry)  Freq(cm-1)  Raman activity  Sym. Ops.
 65 1330.65  68.9754   24
1001330.23  68.9674   24
1101330.50  3066.0811   48
1201330.48  15.1570   48
1301330.47  68.9545   48
1401330.48  68.9536   48
1501330.48  68.9541   48

> In general, I found that when you have problems converging response
> (phonon, epsilon, raman...) calculations it's better to use a much
> stricter conv_thr (i.e. 1.d-12).
> Sometimes I even reduce the hard-coded
> threshold (ethr) in PHonon/PH/set_defaults_pw.f90
  I follow your suggestion and do the calculation.   When
I finish it , I will put it here:)
  There is a parameter tr2_ph in phonon.input.   Could
you please tell me the relation between "ethr" and  "tr2_ph"?

Thank you again:)

-- 

Hui Wang
School of physics, Fudan University, Shanghai, China




On Fri, May 31, 2013 at 12:06 AM, Lorenzo Paulatto
 wrote:
> On 05/30/2013 05:29 PM, xirainbow wrote:
>> I  changes the pseudopotential from "C.pw-mt_fhi.UPF" to
>> "C.pz-hgh.UPF" and get the expected "Raman activity" for different
>> ecutwfc. However, the results of "ecutwfc=110" are still higher than
>> others.
>>
> Compare the output of pw.x at different cutoffs to be sure, my bet is
> that at that specific value of ecutwfc some symmetry operations are
> incompatibles with the FFT grid. It can make convergence harder. In
> general, I found that when you have problems converging response
> (phonon, epsilon, raman...) calculations it's better to use a much
> stricter conv_thr (i.e. 1.d-12). Sometimes I even reduce the hard-coded
> threshold (ethr) in PHonon/PH/set_defaults_pw.f90
>
> bests
>
>
> --
> Dr. Lorenzo Paulatto
> IdR @ IMPMC -- CNRS & Universit? Paris 6
> phone: +33 (0)1 44275 084 / skype: paulatz
> www:   http://www-int.impmc.upmc.fr/~paulatto/
> mail:  23-24/4?16 Bo?te courrier 115, 4 place Jussieu 75252 Paris C?dex 05
>
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[Pw_forum] "Raman activities" do not converge

[xirainbow]

Dear Paolo Giannozzi:

   Thank you very much for your suggestion:)

> I would carefully check the output instead.
   I carefully check the output of ph.x.
   I found the "Raman tensor" does not converge.   Except the
"Raman tensor", I did not find any abnormity.  I increased the kmesh
from 14*14*14 to 20*20*20, but it did not help.  I attache the
"ecutwfc=100, 110" results.

   I  changes the pseudopotential from "C.pw-mt_fhi.UPF" to
"C.pz-hgh.UPF" and get the expected "Raman activity" for different
ecutwfc. However, the results of "ecutwfc=110" are still higher than
others.

 The following is my results.
Using "C.pw-mt_fhi.UPF" :
ecutwfc(Ry)  Freq(cm-1)  Raman activity(A^4/amu)
 65 1330.65   68.9754
1001330.23   68.9674
1101330.50   3066.0811
1201330.48   15.1570
1301330.47   68.9545
1401330.48   68.9536
1501330.48   68.9541


Using  "C.pz-hgh.UPF" :
ecutwfc(Ry)  Freq(cm-1)  Raman activity(A^4/amu)
 70   1330.78  69.6225
 90   1341.85  70.0144
100  1333.32  70.1650
110  1337.38  87.7369
120  1339.90  69.9051
130  1339.60  69.9249
140  1338.35  69.9469
150  1337.71  69.9402



On Thu, May 30, 2013 at 1:27 AM, Paolo Giannozzi
 wrote:
>
> I would carefully check the output instead.
> Two values for the Raman activity are clearly
> outliers in a set of well-behaving data points.
> They are highly suspect.
>
> P.
>
> On Wed, 2013-05-29 at 09:43 -0700, Sanjeev Gupta wrote:
> > Dear Wang
> >
> >
> > In my guess, the converging mostly depends on choosing
> > pseudopotential, so may be it is the problem, that you are not getting
> > converge Raman activity.
> > Otherhand, can you check your structure as well as, but i am not sure.
> >
> >
> > Best
> > Sanjeev
> >
> >
> > On Wed, May 29, 2013 at 5:22 AM, xirainbow 
> > wrote:
> > Dear all:
> > I calculated the "Raman activity" of
> > diamond(Carbon) using QE-5.0.
> > The "Raman activity" changes too much with
> > ecutwfc.
> > Could you give me some help?
> >
> >
> > Calculational results of "Raman activity variation with
> > ecutwfc" ("14*14*14 kmesh).
> >ecutwfc(Ry)  Freq(cm-1)  Raman
> > activity(A^4/amu)
> >65 1330.23  68.9754
> >100   1330.65  68.9674
> >110   1330.50  3066.0811
> >120   1330.48  15.1570
> >130   1330.47  68.9545
> >
> >
> > The following is input of pw.x and ph.x:
> > INPUT of SCF:
> >  &control
> > calculation='scf',
> > disk_io='low',
> > restart_mode='from_scratch',
> > prefix='diamond.$i'
> > pseudo_dir = '/home/lykong/hwang/espresso-5.0/pseudo',
> > outdir='/home/lykong/hwang/tmp'
> >  /
> >  &system
> > ibrav = 0, celldm(1) = 1.8897268436, nat= 2, ntyp= 1,
> > ecutwfc = $i
> >  /
> >  &electrons
> > mixing_beta = 0.7
> > conv_thr =  1.0d-8
> >  /
> > ATOMIC_SPECIES
> >  C   12.01   C.pw-mt_fhi.UPF
> > ATOMIC_POSITIONS {crystal}
> > C   0.0 0.0 0.
> > C   0.25000 0.25000 0.2500
> > CELL_PARAMETERS
> >1.758613117   1.758613117   0.0
> >1.758613117   0.0   1.758613117
> >0.0   1.758613117   1.758613117
> >
> >
> >
> >
> > INPUT of PHONON:
> > phonons of diamond at Gamma
> >  &inputph
> >   tr2_ph=1.0d-14,
> >   alpha_mix=0.7
> >   prefix=

[Pw_forum] "Raman activities" do not converge

[xirainbow]

Dear Sanjeev:

> In my guess, the converging mostly depends on choosing pseudopotential,
 I  changes the pseudopotential from "C.pw-mt_fhi.UPF" to
"C.pz-hgh.UPF" and get the expected "Raman activity" for different ecutwfc.
 Thank you very much :)

 The following is my results.
Using "C.pw-mt_fhi.UPF" :
ecutwfc(Ry)  Freq(cm-1)  Raman activity(A^4/amu)
 65 1330.65   68.9754
1001330.23   68.9674
1101330.50   3066.0811
1201330.48   15.1570
1301330.47   68.9545
1401330.48   68.9536
1501330.48   68.9541


Using  "C.pz-hgh.UPF" :
ecutwfc(Ry)  Freq(cm-1)  Raman activity(A^4/amu)
 70   1330.78  69.6225
 90   1341.85  70.0144
100  1333.32  70.1650
110  1337.38  87.7369
120  1339.90  69.9051
130  1339.60  69.9249
140  1338.35  69.9469
150  1337.71  69.9402


On Thu, May 30, 2013 at 12:43 AM, Sanjeev Gupta
wrote:

> Dear Wang
>
> In my guess, the converging mostly depends on choosing pseudopotential, so
> may be it is the problem, that you are not getting converge Raman activity.
> Otherhand, can you check your structure as well as, but i am not sure.
>
> Best
> Sanjeev
>
>
> On Wed, May 29, 2013 at 5:22 AM, xirainbow  wrote:
>
>> Dear all:
>> I calculated the "Raman activity" of diamond(Carbon) using
>> QE-5.0.
>> The "Raman activity" changes too much with ecutwfc.
>> Could you give me some help?
>>
>> Calculational results of "Raman activity variation with ecutwfc"
>> ("14*14*14 kmesh).
>>ecutwfc(Ry)  Freq(cm-1)  Raman activity(A^4/amu)
>>65 1330.23  68.9754
>>100   1330.65  68.9674
>>110   1330.50  3066.0811
>>120   1330.48  15.1570
>>130   1330.47  68.9545
>>
>> The following is input of pw.x and ph.x:
>> INPUT of SCF:
>>  &control
>> calculation='scf',
>> disk_io='low',
>> restart_mode='from_scratch',
>> prefix='diamond.$i'
>> pseudo_dir = '/home/lykong/hwang/espresso-5.0/pseudo',
>> outdir='/home/lykong/hwang/tmp'
>>  /
>>  &system
>> ibrav = 0, celldm(1) = 1.8897268436, nat= 2, ntyp= 1,
>> ecutwfc = $i
>>  /
>>  &electrons
>> mixing_beta = 0.7
>> conv_thr =  1.0d-8
>>  /
>> ATOMIC_SPECIES
>>  C   12.01   C.pw-mt_fhi.UPF
>> ATOMIC_POSITIONS {crystal}
>> C   0.0 0.0 0.
>> C   0.25000 0.25000 0.2500
>> CELL_PARAMETERS
>>1.758613117   1.758613117   0.0
>>1.758613117   0.0   1.758613117
>>0.0   1.758613117   1.758613117
>>
>>
>> INPUT of PHONON:
>> phonons of diamond at Gamma
>>  &inputph
>>   tr2_ph=1.0d-14,
>>   alpha_mix=0.7
>>   prefix='diamond.$i'
>>   epsil=.true.,
>>   lraman=.true.,
>>   amass(1)=12.01,
>>   outdir='/home/lykong/hwang/tmp'
>>   fildyn='diamond.$i.dynG',
>>   reduce_io=.TRUE.
>>  /
>> 0.0 0.0 0.0
>>
>>
>>
>> --
>> 
>> Hui Wang
>> School of physics, Fudan University, Shanghai, China
>>
>> ___
>> Pw_forum mailing list
>> Pw_forum at pwscf.org
>> http://pwscf.org/mailman/listinfo/pw_forum
>>
>
>
>
> --
> With Best Regards,
>
> 
> Dr. Sanjeev Kumar Gupta
> Fulbright Post-Doctoral Scholar
> Dept. of Physics
> Michigan Technological University
> 1400 Townsend Drive, Houghton
> MI 49931, USA
> 
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>



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Hui Wang
School of physics, Fudan University, Shanghai, China
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[Pw_forum] "Raman activities" do not converge

[xirainbow]

Dear Sanjeev Kumar Gupta:
Thank you very much for your prompt suggestion:)

> In my guess, the converging mostly depends on choosing pseudopotential
I  changes the pseudopotential from "C.pw-mt_fhi.UPF" to
"C.pz-hgh.UPF" and am doing calculation.
As long as I finish the calculation, I will put it here:)

> Otherhand, can you check your structure as well as, but i am not sure.
   I am sure the structure is right:)

   Thank you again:)


On Thu, May 30, 2013 at 12:43 AM, Sanjeev Gupta
wrote:

> Dear Wang
>
> In my guess, the converging mostly depends on choosing pseudopotential, so
> may be it is the problem, that you are not getting converge Raman activity.
> Otherhand, can you check your structure as well as, but i am not sure.
>
> Best
> Sanjeev
>
>
> On Wed, May 29, 2013 at 5:22 AM, xirainbow  wrote:
>
>> Dear all:
>> I calculated the "Raman activity" of diamond(Carbon) using
>> QE-5.0.
>> The "Raman activity" changes too much with ecutwfc.
>> Could you give me some help?
>>
>> Calculational results of "Raman activity variation with ecutwfc"
>> ("14*14*14 kmesh).
>>ecutwfc(Ry)  Freq(cm-1)  Raman activity(A^4/amu)
>>65 1330.23  68.9754
>>100   1330.65  68.9674
>>110   1330.50  3066.0811
>>120   1330.48  15.1570
>>130   1330.47  68.9545
>>
>> The following is input of pw.x and ph.x:
>> INPUT of SCF:
>>  &control
>> calculation='scf',
>> disk_io='low',
>> restart_mode='from_scratch',
>> prefix='diamond.$i'
>> pseudo_dir = '/home/lykong/hwang/espresso-5.0/pseudo',
>> outdir='/home/lykong/hwang/tmp'
>>  /
>>  &system
>> ibrav = 0, celldm(1) = 1.8897268436, nat= 2, ntyp= 1,
>> ecutwfc = $i
>>  /
>>  &electrons
>> mixing_beta = 0.7
>> conv_thr =  1.0d-8
>>  /
>> ATOMIC_SPECIES
>>  C   12.01   C.pw-mt_fhi.UPF
>> ATOMIC_POSITIONS {crystal}
>> C   0.0 0.0 0.
>> C   0.25000 0.25000 0.2500
>> CELL_PARAMETERS
>>1.758613117   1.758613117   0.0
>>1.758613117   0.0   1.758613117
>>0.0   1.758613117   1.758613117
>>
>>
>> INPUT of PHONON:
>> phonons of diamond at Gamma
>>  &inputph
>>   tr2_ph=1.0d-14,
>>   alpha_mix=0.7
>>   prefix='diamond.$i'
>>   epsil=.true.,
>>   lraman=.true.,
>>   amass(1)=12.01,
>>   outdir='/home/lykong/hwang/tmp'
>>   fildyn='diamond.$i.dynG',
>>   reduce_io=.TRUE.
>>  /
>> 0.0 0.0 0.0
>>
>>
>>
>> --
>> 
>> Hui Wang
>> School of physics, Fudan University, Shanghai, China
>>
>> ___
>> Pw_forum mailing list
>> Pw_forum at pwscf.org
>> http://pwscf.org/mailman/listinfo/pw_forum
>>
>
>
>
> --
> With Best Regards,
>
> 
> Dr. Sanjeev Kumar Gupta
> Fulbright Post-Doctoral Scholar
> Dept. of Physics
> Michigan Technological University
> 1400 Townsend Drive, Houghton
> MI 49931, USA
> 
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>



-- 

Hui Wang
School of physics, Fudan University, Shanghai, China
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[Pw_forum] "Raman activities" do not converge

[xirainbow]

Dear all:
I calculated the "Raman activity" of diamond(Carbon) using
QE-5.0.
The "Raman activity" changes too much with ecutwfc.
Could you give me some help?

Calculational results of "Raman activity variation with ecutwfc" ("14*14*14
kmesh).
   ecutwfc(Ry)  Freq(cm-1)  Raman activity(A^4/amu)
   65 1330.23  68.9754
   100   1330.65  68.9674
   110   1330.50  3066.0811
   120   1330.48  15.1570
   130   1330.47  68.9545

The following is input of pw.x and ph.x:
INPUT of SCF:
 &control
calculation='scf',
disk_io='low',
restart_mode='from_scratch',
prefix='diamond.$i'
pseudo_dir = '/home/lykong/hwang/espresso-5.0/pseudo',
outdir='/home/lykong/hwang/tmp'
 /
 &system
ibrav = 0, celldm(1) = 1.8897268436, nat= 2, ntyp= 1,
ecutwfc = $i
 /
 &electrons
mixing_beta = 0.7
conv_thr =  1.0d-8
 /
ATOMIC_SPECIES
 C   12.01   C.pw-mt_fhi.UPF
ATOMIC_POSITIONS {crystal}
C   0.0 0.0 0.
C   0.25000 0.25000 0.2500
CELL_PARAMETERS
   1.758613117   1.758613117   0.0
   1.758613117   0.0   1.758613117
   0.0   1.758613117   1.758613117


INPUT of PHONON:
phonons of diamond at Gamma
 &inputph
  tr2_ph=1.0d-14,
  alpha_mix=0.7
  prefix='diamond.$i'
  epsil=.true.,
  lraman=.true.,
  amass(1)=12.01,
  outdir='/home/lykong/hwang/tmp'
  fildyn='diamond.$i.dynG',
  reduce_io=.TRUE.
 /
0.0 0.0 0.0



-- 

Hui Wang
School of physics, Fudan University, Shanghai, China
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[Pw_forum] Raman result wrong, intensity at 0.0 cm-1 is not zero.

[xirainbow]

Dear Yong:
Can you give the eigenvectors of  the translation and
rotation modes ?

On Thu, May 23, 2013 at 2:31 AM, Yong Xue  wrote:

> Dear All
>
> I have calculated both raman and IR spectrum for SiH4 as given in the
> handson tutorial as well as my own system for my own system composed by C
> and O atoms only.
>  Here is the input for nm
>
> Normal modes for SiH4
>
> &inputph
>
> tr2_ph=1.0d-14,
>
> prefix='sih4',
>
> amass(1)=28.086,
>
> amass(2)=1.008,
>
> outdir='./scratch/',
>
> epsil=.true.,
>
> trans=.true.,
>
> asr=.true.
>
> lraman=.true.
>
> fildyn='sih4.dyn'
>
> /
>
> 0.0 0.0 0.0
> and then in for ir
>
> &input fildyn='sih4.dyn', asr='zero-dim' /
> .
>
> here is the output:
>
> # mode [cm-1] [THz] IR Raman depol.fact
>
> 1 0.00 0. 0. 0.0154 0.7500
>
> 2 0.00 0. 0. 0.0884 0.7500
>
> 3 0.00 0. 0. 0.1187 0.7500
>
> 4 0.00 0. 0. 0.1189 0.7500
>
> 5 0.00 0. 0. 0.0412 0.7500
>
> 6 0.00 0. 0. 0.0090 0.7500
>
> 7 634.63 19.0257 1.0901 1.1141 0.7500
>
> 8 634.63 19.0257 1.0901 1.1141 0.7500
>
> 9 634.63 19.0257 1.0901 1.1141 0.7500
>
> 10 819.64 24.5723 0. 8.4695 0.7500
>
> 11 819.64 24.5723 0. 8.4695 0.7500
>
> 12 2524.20 75.6735 0. 267.0320 0.
>
> 13 2546.54 76.3432 3.3785 81.6286 0.7500
>
> 14 2546.54 76.3432 3.3785 81.6286 0.7500
>
> 15 2546.54 76.3432 3.3785 81.6286 0.7500
> .
>
>
> # mode [cm-1] [THz] IR Raman depol
>
> 1 0.00 0. 0. 15.6747 0.0716
>
> 2 0.00 0. 0. 0.7718 0.1430
>
> 3 0.00 0. 0. 0.1764 0.1189
>
> 4 0.00 0. 0. 0.4255 0.1622
>
> 5 0.00 0. 0. 1.5205 0.6017
>
> 6 0.00 0. 0. 5.1010 0.3780
>
> 7 358.03 10.7335 0.2584 1.0997 0.7492
>
> 8 492.33 14.7598 0.8213 11.7392 0.0331
>
> 9 626.56 18.7838 2.0445 5.0328 0.0397
>
> 10 740.99 22.2145 19.5106 7.7263 0.0625
>
> 11 834.76 25.0256 2.7362 1.6688 0.6909
>
> 12 878.99 26.3514 9.5905 2.4451 0.7100
>
> 13 913.65 27.3904 32.8439 0.2926 0.0616
>
> 14 923.23 27.6778 39.7587 2.1247 0.6109
>
> 15 997.29 29.8981 6.8952 6.7520 0.2172
>
> 16 1054.03 31.5990 1.6671 0.9369 0.7237
>
> 17 1070.32 32.0875 11.7048 3.5030 0.7498
>
> 18 1097.04 32.8883 2.0314 3.0010 0.7119
>
>
> Thanks in advance
>
> Xue
>
>
>
>
> --
> Ms. Xue  Yong(??)
> Department of Physics and Engineering Physics
> University of Saskatchewan
> 116 Science Place
> Saskatoon, SK S7N 5E2
> Canada
> Tel: +1 306 261 2369
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>



-- 

Hui Wang
School of physics, Fudan University, Shanghai, China
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[Pw_forum] ”wrong representation“ from ”set_irr_sym“

[xirainbow]

Dear all:
  I run ph.x (PHonon-5.0) with the error below:
*" from set_irr_sym : error #   811*
* wrong representation "*

 I followed the instruction at here (
http://qe-forge.org/pipermail/pw_forum/2012-July/099123.html) and changed
the 258 line in PH/set_irr.f90 to "*(ABS(eigen(imode)) + ABS (eigen (jmode)
)) < 1.d0) ) THEN*".
 But my computation failed.
 Can you give me any suggestion?
 Thanks in advance ??

The following is my input file:
SCF calulation:
 &control
 calculation='scf',
 disk_io='low',
 restart_mode='from_scratch',
 prefix='BH'
 pseudo_dir = '/espresso-5.0/pseudo',
 outdir='/tmp'
  /
  &system
 ibrav = 0, celldm(1) = 1.8897268436, nat= 8, ntyp= 2,
 ecutwfc = 55.0
 ecutrho = 450.0
 occupations = 'fixed'
  /
  &electrons
 mixing_beta = 0.7
 conv_thr =  1.0d-8
  /
 ATOMIC_SPECIES
  H   1.008  H.pbe-rrkjus_psl.0.1.UPF
  B   10.81  B.pbe-n-rrkjus_psl.0.1.UPF
 ATOMIC_POSITIONS {crystal}
 H0.066715364   0.527911320   0.25085
 H0.933284621   0.472088680   0.74915
 H0.933283444   1.027910222   0.25110
 H0.066716541  -0.027910219   0.74890
 B0.377908845   0.411526837   0.25973
 B0.622091155   0.588473193   0.74027
 B0.622092381   0.911528447   0.250001039
 B0.377907619   0.088471531   0.749998961
 K_POINTS {automatic}
   8 10 12 0.0 0.0 0.0
 CELL_PARAMETERS
3.425048353   0.0   0.0
0.0   2.822880790   0.0
0.0   0.0   2.643342353


PHonon calulation:
&inputph
   tr2_ph=1.0d-14,
   alpha_mix=0.7
   ldisp=.true.,
   nq1=4, nq2=5, nq3=6
   prefix='BH'
   amass(1)=1.008,
   amass(2)=10.81,
   outdir='/tmp'
   fildyn='BH.dynG',
   reduce_io=.TRUE.
  /




-- 

Hui Wang
School of physics, Fudan University, Shanghai, China
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[Pw_forum] gap width in dos and band

[xirainbow]

Dear shiva mokhavat:
 Make sure that both "the top of valenc band" and " the bottom of
conducting band" locate on your band path.

On Sun, May 12, 2013 at 5:58 PM, shiva mokhavat wrote:

> dear users
> I am working on GaP compound.I found that experimental studies show 2.35
> ev width for it's band gap. when I run bands.x the gap widht is 2.20 ev,
> but when I run dos.x the gap width is 1.45 ev.I used tetrahedra for nscf in
> dos, but use smearig for band. I attached my input files. I use espresso 4.3
> could anyone help me in this?
> thanks
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>



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Hui Wang
School of physics, Fudan University, Shanghai, China
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[Pw_forum] Charge density at any k-point in the Brillouin zone

[xirainbow]

Dear Koushik:
   In the following website, I gave an example of graphene
nano-ribbon. I hope it is useful to you   ??
http://blog.sina.com.cn/s/blog_5f15ead20100d3wp.html

On Sat, May 4, 2013 at 1:37 PM, koushik pal
wrote:

> Dear Prof. Paulatto,
> I want to know one more thing about charge density visualization. If I
> have understood properly your answer , to visualize the contribution from a
> specific point "k" and band "n", which is the square modulus of the
> wavefunction
> \psi_{k,n}, first I have to do a scf calculation on a regular k-mesh,
> secondly I have to do a nscf calculation at that particular "kpoint" in the
> BZ and then I have to run pp.x  with "plot_num =7" and "*kpoint =1" (is
> this correct?*).
> I am not sure about *"kpoint=1"* because in the scf output file
> "kpoint=1" means the \Gamma point.
>
> Thanks a lot.
>
> With Regards,
> Koushik
> MS student
> JNCASR
> Bangalore-560064
> India
>
>
> > Dear PW users,
> > I need some clarifications on the input file of pp.x. In the &inputpp
> > namelist, what does the "kpoint" mean?
> > To be specific, If I want to visualize the charge density of a
> > particular band ("kband") at any arbitrary k-point in the Brillouin
> > zone (e.g at Gamma (0, 0, 0) and Z(0, 0, 0.5)) what "kpoint" (integer)
> > values should I specify  in each case in the &inputpp namelist?
> > Thanks in advance.
> Dear Koushik,
> the charge density is obtained after a sum over the occupied k-points
> and bands, so you cannot print it for a single k-point.
>
> On the other hand, you can plot the contribution from a specific point
> "k" and band "n", which is the square modulus of the wavefunction
> \psi_{k,n}.
>
> The value of "kpoint" in &inputpp is the index of the k-point, as listed
> in the output of pw.x. If you want to plot a specific point that is not
> in the list you will have to do a nscf calculation first.
>
> best regards
>
> --
> Dr. Lorenzo Paulatto
> IdR @ IMPMC -- CNRS & Universit? Paris 6
> phone: +33 (0)1 44275 084 / skype: paulatz
> www:   http://www-int.impmc.upmc.fr/~paulatto/
> mail:  23-24/4?16 Bo?te courrier 115, 4 place Jussieu 75252 Paris C?dex 05
> -- *
> *
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>



-- 

Hui Wang
School of physics, Fudan University, Shanghai, China
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[Pw_forum] Electro-optic tensor contribution

[xirainbow]

Dear all:
   In the Electro-optic tensor calculation, it writes in the OUTPUT
file:
*"  Electro-optic tensor: contribution #   1*
*.*
*  Electro-optic tensor: contribution #   2*
*"*

   Which one is ionic contribution? Which one is electronic
contribution?

  Thanks in advance ??

-- 

Hui Wang
School of physics, Fudan University, Shanghai, China
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[Pw_forum] Slip in comments of dynmat.f90

[xirainbow]

Dear developer:

  In PHonon-5.0.2.tar.gz, there is a very little slip in the 70 line of
dynmat.f90?
!  filxsf  character as above, in axsf format suitable for xcrysden
!(default: filmol='dynmat.axsf')

  The "default: fil*mol*='dynmat.axsf'" should be changed to "default:*
*fil*xsf*='dynmat.axsf'"

-- 

Hui Wang
School of physics, Fudan University, Shanghai, China
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[Pw_forum] Not convergence of the scf in phonon calculation

[xirainbow]

Dear Li:
  Maybe, you can try to use other  "diagonalization method".
  This parameter can not be set in ph.in. You can edit the
routine "set_defaults_pw.f90".
http://qe-forge.org/pipermail/pw_forum/2013-April/101514.html
  I hope this can give some help:)

On Mon, Apr 29, 2013 at 5:28 PM, GAO Zhe  wrote:
>
> First of all, please make sure that the model you computed has been fully 
> relaxed. Then, while the model was big, the lower alpha_mix(1), default as 
> 0.7, may be helpful for the SCF convergence during ph.x process.
>
> --
> GAO Zhe, Dr.,
> Research Engineer, Quartz,
> Saint-Gobain Research (Shanghai),
> No. 55, Wenjing-road, Minhang-district, Shanghai, China
>
> At 2013-04-29 09:47:18,"???" <18733462676 at 163.com> wrote:
>
> dear all
>when I computed the scf of phonon,the convergnece is always not 
> attained,I tried changing the "tr2_ph" and "alpha_mixing" to accelarate the 
> speed of convergnece ,But the results is not ideal.So i want to know what can 
> i do to perform the convergence of phonon.e.g.which parameters can be changed 
> ?
>
>
>
>
> ??
>
>
>
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum




--

Hui Wang
School of physics, Fudan University, Shanghai, China

[Pw_forum] murnaghan : bct

[xirainbow]

Dear  Sakhraoui Taoufik:
 I think ev.x can only deal with ?fcc, bcc, sc and hex? crystal
structure.

On Sun, Apr 28, 2013 at 7:36 PM, Sakhrawi Taoufek wrote:

> dear all,
> when i want to fit with murnaghan eos with ev.x, i should choose the
> structure (fcc, bcc, sc or hex)
> >>> Enter type of bravais lattice (fcc, bcc, sc, hex)
> in my case i work with bct (body centered tetragonal) stucture.
> what type of structure should i use??
> thanks in advance
>
>
> 
> Sakhraoui Taoufik
> Phd student, LMCN
> Monastir, Tunisia
> 
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>



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Hui Wang
School of physics, Fudan University, Shanghai, China
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[Pw_forum] How to set "electrons" parameters in ph.x ?

[xirainbow]

Dear Paolo Giannozzi:

> as long as you get convergence, it doesn't matter which diagonalization
>  algorithm and which mixing parameter you use
  I *get convergence* in *pw.x*, but *fail *to get convergence in *
ph.x*.

> you cannot from input. You have to edit routine "set_defaults_pw.f90"
 Thank you very much  for your prompt help :)

-- 

Hui Wang
School of physics, Fudan University, Shanghai, China


On Mon, Apr 15, 2013 at 2:58 PM, Paolo Giannozzi
wrote:

> On Mon, 2013-04-15 at 13:59 +0800, xirainbow wrote:
>
> > In my calculations(QE 5.0), the "beta" and "diagonalization" in
> > *.ph.out of ph.x is different from the *.scf.out file of pw.x.
>
> as long as you get convergence, it doesn't matter which diagonalization
> algorithm and which mixing parameter you use
>
> > However, in the *.ph.out file, I  find:
> > "beta  =0.7000
> > Davidson diagonalization with overlap"
>
> the "beta" parameter is not actually used in phonon calculations, IIRC
>
> > How to set the "mixing_beta and diagonalization" parameters in ph.x?
>
> you cannot from input. You have to edit routine "set_defaults_pw.f90"
>
> P.
>
> --
>  Paolo Giannozzi, Dept. Chemistry&Physics&Environment,
>  Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
>  Phone +39-0432-558216, fax +39-0432-558222
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>
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[Pw_forum] How to set "electrons" parameters in ph.x ?

[xirainbow]

Dear all:

  In my calculations(QE 5.0), the *"beta"* and *"diagonalization"*
 in **.ph.out* of *ph.x* is different from the **.scf.out* file of *pw.x*.

   I set
*"mixing_beta = 0.3*
*diagonalization = 'cg'  " *
in scf calculation(pw.x). Then, I find the right parameters in *.scf.out
file.

   However, in the **.ph.out* file, I  find:
*"beta  =0.7000*
*Davidson diagonalization with overlap"*
in *.ph.out file.

   How to set the "*mixing_beta *and* diagonalization*" parameters
in *ph.x*?

   Thanks in advance:)


-- 

Hui Wang
School of physics, Fudan University, Shanghai, China
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[Pw_forum] Bug in matdyn.f90

[xirainbow]

Dear developer:
  I notice a little bug in matdyn.f90.
  I think the 657 line of matdyn.f90 is not compatable with the
 *.fc file generated by q2r.x (QE Version 5.0).

  From 655 to 659 lines of matdyn.f90, it is:
*READ(1,*) ntyp,nat,ibrav,(celldm(i),i=1,6)*
*if (ibrav==0) then*
*read(1,'(a)') atm ! for compatibility*
*read(1,*) ((at(i,j),i=1,3),j=1,3)*
*end if*

 The *.fc file generated by q2r.x looks like:
*10  0  4.1119002  0.000  0.000  0.000  0.000  0.000*
*-1.1303201321.1303201321.130320132*
* 1.130320132   -1.1303201321.130320132*
* 1.1303201321.130320132   -1.130320132*

 As you can see, "* read(1,'(a)') atm ! for compatibility*" of
matdyn.x will read the second line of *.fc (*-1.1303201321.130320132
 1.130320132*). Therefore, "*read(1,*) ((at(i,j),i=1,3),j=1,3)*" of
matdyn.x will fail with the error message"forrtl: severe (64): input
conversion error, unit 1, file /home/lykong/hwang/N6B4/phonon/N6B4.0Gpa.fc"

 I hope my report is right :)
 Thank you very much  :)

-- 

Hui Wang
School of physics, Fudan University, Shanghai, China
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[Pw_forum] Non zero "Effective Charges" of Silicon in "example02"

[xirainbow]

Dear all:

 I ran the "example-4.3.2/examples/example02" and got the
"si.dynG" file.
 In the "si.dynG" file, the "Effective Charges of Silicon" was :
*" Effective Charges E-U: Z_{alpha}{s,beta}*
* atom #1*
* -0.075683653870  0.  0.*
*  0. -0.075683653870  0.*
*  0.  0. -0.075683653870*
* atom #2*
* -0.075683653870  0.  0.*
*  0. -0.075683653870  0.*
*  0.  0. -0.075683653870*
*"*
Obviously, the "Effective Charges" of the two atoms do not
satisfy the "sum rule".
Can I take  -0.075683653870 as zero?  If so, what is the
precision of  calculated  "Effective Charges" ?

Thanks in advance ??

-- 

Hui Wang
School of physics, Fudan University, Shanghai, China
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[Pw_forum] A little energy gap (~ 0.2 eV) for graphene

[xirainbow]

Please make sure that the Kpoint of the primitive grephene unit cell is
included in your kmesh.

On Mon, May 21, 2012 at 8:13 PM, Cao TF  wrote:

> **
> Dear QE users,
> I have calculated the density of states (DOS) of pure graphene. The
> supercell used in my work is a rectangular cell containing 60 carbon atoms.
> But something has puzzled me greatly. There is always a little energy gap
> (~0.2 eV) in the DOS, which contracts with the fact that graphene is zero
> gap semiconductor. Although I have change many parameters. This problem has
> not been solved. Here I give the input file and I will be greatly
> appreciated if you can give me some suggestions.
> For scf.in
> &CONTROL
> title = 'graphene layer' ,
> calculation = 'scf' ,
> restart_mode = 'from_scratch' ,
> outdir = './tmp' ,
> pseudo_dir = '~pseudo' ,
> prefix = 'graphene' ,
> /
> &SYSTEM
> ibrav = 8 ,
> a = 12.31 , b = 12.79312342 , c = 12.000 ,
> nat = 60 ,
> ntyp = 1 ,
> occupations = 'smearing' ,
> tot_charge = 0.0,
> degauss = 0.02 ,
> smearing = 'mp' ,
> nspin = 2 ,
> starting_magnetization(1) = 0.5 ,
> ecutwfc = 30.0 ,
> ecutrho = 300.0 ,
> /
> &ELECTRONS
> conv_thr = 1.0d-8 ,
> mixing_mode = 'local-TF' ,
> mixing_beta = 0.7 ,
> diagonalization = 'david' ,
> /
> ATOMIC_SPECIES
> C 12.0107 C.pbe-rrkjus.UPF
> ATOMIC_POSITIONS crystal
> C 0.000 0.000 0.5000
> C 0.1000 5.5671E-02 0.5000
> C 0.1000 0.1667 0.5000
> C 0.000 0.2224 0.5000
> C 0.000 0.3334 0.5000
> C 0.1000 0.3890 0.5000
> C 0.1000 0.5000 0.5000
> C 0.000 0.5558 0.5000
> C 0.000 0.6669 0.5000
> C 0.1000 0.7227 0.5000
> C 0.1000 0.8337 0.5000
> C 0.000 0.8896 0.5000
> C 0.2000 0.000 0.5000
> C 0.3001 5.5671E-02 0.5000
> C 0.3001 0.1667 0.5000
> C 0.2000 0.2224 0.5000
> C 0.2000 0.3334 0.5000
> C 0.3001 0.3890 0.5000
> C 0.3001 0.5000 0.5000
> C 0.2000 0.5558 0.5000
> C 0.2000 0.6669 0.5000
> C 0.3001 0.7227 0.5000
> C 0.3001 0.8337 0.5000
> C 0.2000 0.8896 0.5000
> C 0.4001 0.000 0.5000
> C 0.5000 5.5671E-02 0.5000
> C 0.5000 0.1667 0.5000
> C 0.4001 0.2224 0.5000
> C 0.4001 0.3334 0.5000
> C 0.5000 0.3890 0.5000
> C 0.5000 0.5000 0.5000
> C 0.4001 0.5558 0.5000
> C 0.4001 0.6669 0.5000
> C 0.5000 0.7227 0.5000
> C 0.5000 0.8337 0.5000
> C 0.4001 0.8896 0.5000
> C 0.6002 0.000 0.5000
> C 0.7005 5.5671E-02 0.5000
> C 0.7005 0.1667 0.5000
> C 0.6002 0.2224 0.5000
> C 0.6002 0.3334 0.5000
> C 0.7005 0.3890 0.5000
> C 0.7005 0.5000 0.5000
> C 0.6002 0.5558 0.5000
> C 0.6002 0.6669 0.5000
> C 0.7005 0.7227 0.5000
> C 0.7005 0.8337 0.5000
> C 0.6002 0.8896 0.5000
> C 0.8001 0.000 0.5000
> C 0.9004 5.5671E-02 0.5000
> C 0.9004 0.1667 0.5000
> C 0.8001 0.2224 0.5000
> C 0.8001 0.3334 0.5000
> C 0.9004 0.3890 0.5000
> C 0.9004 0.5000 0.5000
> C 0.8001 0.5558 0.5000
> C 0.8001 0.6669 0.5000
> C 0.9004 0.7227 0.5000
> C 0.9004 0.8337 0.5000
> C 0.8001 0.8896 0.5000
> K_POINTS automatic
> 8 8 1 0 0 0
> For nscf.in
> &CONTROL
> title = 'graphene layer' ,
> calculation = 'nscf' ,
> restart_mode = 'from_scratch' ,
> outdir = './tmp' ,
> pseudo_dir = '/lustre/ISSP2/tfcao/pseudo' ,
> prefix = 'graphene' ,
> /
> &SYSTEM
> ibrav = 8 ,
> a = 12.31 , b = 12.79312342 , c = 12.000 ,
> nat = 60 ,
> ntyp = 1 ,
> occupations = 'tetrahedra' ,
> tot_charge = 0.0,
> nspin = 2 ,
> starting_magnetization(1) = 0.5 ,
> ecutwfc = 30.0 ,
> ecutrho = 300.0 ,
> /
> &ELECTRONS
> conv_thr = 1.0d-8 ,
> mixing_mode = 'local-TF' ,
> mixing_beta = 0.7 ,
> diagonalization = 'david' ,
> /
> ATOMIC_SPECIES
> C 12.0107 C.pbe-rrkjus.UPF
> For dos.in
> &inputpp
> prefix = 'graphene' ,
> outdir = './tmp' ,
> Emin = -4.0 ,
> Emax = 4.0 ,
> DeltaE = 0.01 ,
> fildos = graphene.dos ,
> /
> The accessory is the DOS I have got.
> I am sorry for such a long file. I hope that you can give some
> suggestions.
> ==
> Tengfei Cao, Research Laboratory for Computational Materials Sciences,
> Instutue of Solid State Physics,the Chinese Academy of Sciences,
>
> ==
>
>
>
>
>
>
> 93,2 ??
> 1,2 ??
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>
>


-- 

Hui Wang
Sc

[Pw_forum] How to realize the parallel calculation?

[xirainbow]

Dear Tao:

On Fri, Sep 2, 2011 at 8:08 AM, ??  wrote:

> Dear all,
>
> The mpi run is used in my calculation, but I hear of that the kpoints
> cannot be allocated to every cpu unless a parameter is specified in the
> input file.

I don't think so. In my experience(a personal computer, not cluster), I just
need type "mpirun -np 4 ". "4" is the number of cores.
In general, the number of kpoints should be divided by the number of cores.




>
> So, dear professors, would you tell me what is the parameter?
>
> Thanks a lot!
>
> Plato Tao
>
>
>
>
>
>
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>



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School of physics, Fudan University, Shanghai, China
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[Pw_forum] Raman Spectra of Molecular Crystals

[xirainbow]

Dear Kacper Dru?bicki:
 Read the document in your installation directory :
/espresso-XXX/examples/README carefully. Then you will find what you need:)

2011/8/29 "Kacper Dru?bicki" 

> Dear QE Users,
>
> My name is Casper and I am a newbie in Quantum Espresso with some
> experience in modeling with other periodic codes (mainly CASTEP and DMOL3).
> Please forgive me bothering you with my question. I don't want to spam QE
> maillist, but I would like to kindly ask someone for some help in modeling
> of vibrational spectra of molecular crystals. Could anyone send me any
> exemplary input which allows to compute IR and Raman spectra of any simple
> system? I am rather disoriented while reading some manuals etc. and I am not
> sure how to start. I would really appreciate your help.
>
> With best wishes,
> Casper
>
> Kacper Dru?bicki,
> Faculty of Chemistry,
> Department of Chemical Physics,
> Jagiellonian University,
> Ingardena Street 3, 30-060 Krak?w, Poland
> phone: +48 12 6632265
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>



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School of physics, Fudan University, Shanghai, China
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[Pw_forum] Three questions about phonon calculation

[xirainbow]

Dear Yu Han Ho:

2011/6/1 yhho 

>  Dear all,
> I have some questions about Phonon calculation.
>
> 1. If I use ph.x to run the graphene phonon dispersion and pdos,
> should I use the q points which is multiple of 6 because of the
> hexagonal shape of grathpene crystal?
>
I do not think so. But before calculation, you must know which q points you
want to get.


>
> 2. When I run phonon-dispersion calculation, it always cost very long cpu
> time. Is that normal?
>
Phonon calculation always costs more time than electron scf calculation.
Approximately, each q point needs 3*n scf calculation(n is the number of
atoms in primitive unit cell).


>
> 3. Can QE calculate vibration mode?
>
Yes , of course.

> How could I set terms in ph.in to get vibration mode?
>
Searching in google.

> And how could I plot the vibration mode from the output file?
>
I do not think you can plot it with QE.


>
> Thanks a lot.
>
> best regards,
> Yu Han Ho
>
>
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>
>


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Hui Wang
School of physics, Fudan University, Shanghai, China
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[Pw_forum] energy/force/stress obtained from scf versus vc-relax

[xirainbow]

Dear Amin:

On Sat, May 28, 2011 at 2:26 AM, Amin Torabi  wrote:

> Dear all,
>
> I did a vc-relax calculation. Then, I used the cell_parameters and
> atomic_positions obtained at the end of vc-relax to do an scf calculation. I
> didn't change any other settings, like k-point or ecutoff.
> However, the total energy, the total force and the total stress obtained
> from the scf calculation are different form the values obtained at the end
> of the vc-relax calculation. (The vc-relax values are lower.)
>  Why is it so?
>
You are right.
When you do vc-relax, the G points contained in wave-function does not
change with the cell parameters(That means the energy cutoff changes when
cell parameters change during vc-relax). When you do scf after vc-relax, the
cell parameters of scf is different from that of vc-relax.
Therefore, the G points contained in wave-function of scf differs from that
of vc-relax.
Usually, you should do the second vc-relax  if the cell parameters change a
lot. After the second vc-relax, the force/stress of scf will be close to
that of second vc-relax.


>
>
> Thanks is advance.
>
> Amin
>
> ___
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>
>


-- 

Hui Wang
School of physics, Fudan University, Shanghai, China
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[Pw_forum] LO-TO splitting

[xirainbow]

Dear Bipul Rakshit:
As long as you can get the "effectiv charge" of AFM insulator, you can get
the LO-TO splitting.
However, I think it is difficult to deal with the "effective charge" of AFM
insulator.

Maybe this could give you some help:)
http://www.democritos.it/pipermail/pw_forum/2011-January/019131.html

On Fri, May 27, 2011 at 11:13 AM, Bipul Rakshit  wrote:

> Dear PWSCF users,
> is it possible/implemented in PWSCF to get lo-to splitting in case of
> anti-ferro magnetic insulator compounds?
> thx
>
> --
> Bipul Rakshit
> Research Associate,
> S N Bose Centre for Basic Sciences,
> Salt Lake,
> Kolkata 700 098
> India
> ___
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> Pw_forum at pwscf.org
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>



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School of physics, Fudan University, Shanghai, China
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[Pw_forum] Can pwscf calculate the structure of charged slab ?

[xirainbow]

Dear Swapnil:

 Dear pwscf users,
> I wonder if pwscf is capable of calculating the equilibrium structure of
> charged system, e.g., charged 2D slab. As I know VASP is unable to calculate
> the energe of charged slab, what about pwscf?
>
I beg to differ.
As far as I know, both vasp ans QE can deal with charged system.
If you searched "charged  pwscf" or "charged vasp", you will get a lot of
helpful results.




> Thanks!
>
> 2011-05-12
> --
>  taoohee
>

> Pw_forum mailing list
> Pw_forum at pwscf.org
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>
>


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School of physics, Fudan University, Shanghai, China
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[Pw_forum] charge density

[xirainbow]

Dear vicky singh:


> I am studying the effect of alloying on a supercell with 40 atoms. I am
> replacing one Ni with different alloying elements. To get the charge density
> should i relax the system and the perform the scf or simple scf will give
> the effect of alloying.
>
I do not think there is simple answer. It depends on what you are interested
and the computer power.
You could find how other people do it in published papers.



> vicky singh
> research student
> Bangalore
>
> ___
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>
>


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School of physics, Fudan University, Shanghai, China
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[Pw_forum] Doubt in band plot

[xirainbow]

Dear Padmaja Patnaik:

 I am plotting band structure for cubic SiC. Got good shape when compared.
> SiC has an indirect band gap. Next I tried to plot the band structure of
> cubic SIC with a supercell. I have expanded the lattice constant by twice in
> all direction and generated supercell with Phonon code. Now the band plot of
> this supercell shows direct band gap. how is this possible? It is expected
> that even if the supercell should produce the same band plot.

When you expand the lattice constant, the Brillouin Zone will be folded.
Therefore, the indirect gap may turn into direct gap.
If you plot the dos, the primitive cell and supercell will give the same
shape, but the bands are different.

Please suggets.
>
> Thanking in advance
> regards
> Padmaja Patnaik
> Research Scholar
> Dept of Physics
> IIT Bombay
> Mumbai, India
> ___
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>


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Hui Wang
School of physics, Fudan University, Shanghai, China
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[Pw_forum] the unit of DOS

[xirainbow]

I am sure the unit of DOS is
 states/eV/(unit cell)
The unit of pdos is
* states/eV/atom*

On Fri, May 6, 2011 at 6:22 PM, mashiat alaaii wrote:

> Hello,
> what is the unit of DOS?
> Should I divide the DOS that QE provides to the volume of slab?
> Thank you
> Alaaii
>
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>


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[Pw_forum] smearing

[xirainbow]

Dear P Shok:

Is there a limit that all smearings converge? For instance, is it possible
> to say that in very small degauss, all smearings give the same result?
>
I think so.
You can find some example at here:
http://blog.sina.com.cn/s/blog_5f15ead20100d1ki.html

However, keep in mind: small degauss must be used with large k-mesh.

Thank you for your help.
> P Shok
>
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>


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School of physics, Fudan University, Shanghai, China
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[Pw_forum] Graphene Nanoribbon

[xirainbow]

Dear Swapnil Chandratre:

Thank you for your quick response, but is it not required to satisfy the
> dangling bonds with h2 passivation (as I see just the C atoms here).
>
You have to add H by yourself.
Do not you know how to add atoms?


> The other query I had is Graphene is Semi Metallic, it can show semi
> conducting properties if designed in ArmChair configuration with proper
> geometry, is there any specific thing to keep in mind if I want to explore
> that aspect.
>
I think you should know how to explore semi metallic property of two
dimensional graphene, before dealing with nanoribbon. If you don't know the
origin of semi-metallic graphene, you would not know how to explore it in
nanoribbon.


>
>
> On Mon, May 2, 2011 at 9:54 PM, xirainbow  wrote:
>
>> Dear Swapnil Chandratre:
>> The following is my input file for graphenen ribbon6 for QE4.0.
>> You can find more information at here:
>> http://blog.sina.com.cn/s/blog_5f15ead20100drss.html
>>
>> #
>> INPUT FILE OF GRAPHENE RIBBON 6
>> Input file:graphene.rx.in
>> &CONTROL
>>  calculation = 'relax' ,
>> restart_mode = ??
>>   outdir = ??
>>   pseudo_dir = ??
>>etot_conv_thr = 1.0e-4 ,
>>forc_conv_thr = 1.0e-3 ,
>>  tstress = .true. ,
>>  tprnfor = .true. ,
>>  /
>>  &SYSTEM
>>ibrav = 8,
>>celldm(1) = 4.67689278,
>>celldm(2) = 8.623989813,
>>celldm(3) = 4.048794087,
>>  nat = 12,
>> ntyp = 2,// the largest ntype=10
>>  ecutwfc = 60.D0 ,
>>  ecutrho = 500.D0 ,
>>nosym = .false. ,
>> nbnd = 36,
>>nelec = 48,
>>  occupations = 'smearing' ,
>>  degauss = 0.02 ,
>> smearing = 'gaussian' ,
>>nspin = 2 ,
>>starting_magnetization(1) = 1.0,
>>starting_magnetization(2) = -0.5,
>>  /
>>  &ELECTRONS
>> conv_thr = 1.D-6 ,
>>  mixing_mode = 'plain' ,
>>  mixing_beta = 0.7D0 ,
>>  diagonalization = 'david' ,
>> diago_david_ndim = 8,
>>  /
>>  &IONS
>> ion_dynamics = 'damp' ,
>>pot_extrapolation = 'second_order' ,
>>wfc_extrapolation = 'second_order' ,
>>  /
>> ATOMIC_SPECIES
>>C1   12.0  C.pbe-rrkjus.UPF
>>C2   12.0  C.pbe-rrkjus.UPF
>> ATOMIC_POSITIONS crystal
>>C1  0.00.2364655420.0
>>C2  0.50.2654564860.0
>>C1  0.50.3340924170.0
>>C2  0.00.3667728140.0
>>C1  0.00.4336737570.0
>>C2  0.50.4666400350.0
>>C1  0.50.5333601680.0
>>C2  0.00.5663262320.0
>>C1  0.00.6332271300.0
>>C2  0.50.6659074750.0
>>C1  0.50.7345433490.0
>>C2  0.00.7635345960.0
>> K_POINTS automatic
>>   13 1 1   0 0 0
>>
>>
>>
>> <http://blog.sina.com.cn/s/blog_5f15ead20100drss.html>
>>
>> On Tue, May 3, 2011 at 5:18 AM, swapnil chandratre <
>> swapnil.chandratre at gmail.com> wrote:
>>
>>> Hi,
>>>
>>> I am new to Espresso, I am trying to work with Graphene Nanoribbon(1-d),
>>> though I am spending individual  time on understanding how to use the
>>> software and implement conditions accordingly, can anyone provide a sample
>>> input file for a GNR?
>>>
>>> --
>>> Regards,
>>> Swapnil Chandratre
>>> Graduate Student
>>> Dept. of Mechanical Engineering,
>>> University of Houston,
>>> Houston, TX
>>> (M)-713-294-9546
>>>
>>> ___
>>> Pw_forum mailing list
>>> Pw_forum at pwscf.org
>>> http://www.democritos.it/mailman/listinfo/pw_forum
>>>
>

[Pw_forum] Graphene Nanoribbon

[xirainbow]

Dear Swapnil Chandratre:
The following is my input file for graphenen ribbon6 for QE4.0.
You can find more information at here:
http://blog.sina.com.cn/s/blog_5f15ead20100drss.html

#
INPUT FILE OF GRAPHENE RIBBON 6
Input file:graphene.rx.in
&CONTROL
 calculation = 'relax' ,
restart_mode = ??
  outdir = ??
  pseudo_dir = ??
   etot_conv_thr = 1.0e-4 ,
   forc_conv_thr = 1.0e-3 ,
 tstress = .true. ,
 tprnfor = .true. ,
 /
 &SYSTEM
   ibrav = 8,
   celldm(1) = 4.67689278,
   celldm(2) = 8.623989813,
   celldm(3) = 4.048794087,
 nat = 12,
ntyp = 2,// the largest ntype=10
 ecutwfc = 60.D0 ,
 ecutrho = 500.D0 ,
   nosym = .false. ,
nbnd = 36,
   nelec = 48,
 occupations = 'smearing' ,
 degauss = 0.02 ,
smearing = 'gaussian' ,
   nspin = 2 ,
   starting_magnetization(1) = 1.0,
   starting_magnetization(2) = -0.5,
 /
 &ELECTRONS
conv_thr = 1.D-6 ,
 mixing_mode = 'plain' ,
 mixing_beta = 0.7D0 ,
 diagonalization = 'david' ,
diago_david_ndim = 8,
 /
 &IONS
ion_dynamics = 'damp' ,
   pot_extrapolation = 'second_order' ,
   wfc_extrapolation = 'second_order' ,
 /
ATOMIC_SPECIES
   C1   12.0  C.pbe-rrkjus.UPF
   C2   12.0  C.pbe-rrkjus.UPF
ATOMIC_POSITIONS crystal
   C1  0.00.2364655420.0
   C2  0.50.2654564860.0
   C1  0.50.3340924170.0
   C2  0.00.3667728140.0
   C1  0.00.4336737570.0
   C2  0.50.4666400350.0
   C1  0.50.5333601680.0
   C2  0.00.5663262320.0
   C1  0.00.6332271300.0
   C2  0.50.6659074750.0
   C1  0.50.7345433490.0
   C2  0.00.7635345960.0
K_POINTS automatic
  13 1 1   0 0 0





On Tue, May 3, 2011 at 5:18 AM, swapnil chandratre <
swapnil.chandratre at gmail.com> wrote:

> Hi,
>
> I am new to Espresso, I am trying to work with Graphene Nanoribbon(1-d),
> though I am spending individual  time on understanding how to use the
> software and implement conditions accordingly, can anyone provide a sample
> input file for a GNR?
>
> --
> Regards,
> Swapnil Chandratre
> Graduate Student
> Dept. of Mechanical Engineering,
> University of Houston,
> Houston, TX
> (M)-713-294-9546
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>
>


-- 

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School of physics, Fudan University, Shanghai, China
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[Pw_forum] LO-TO splitting in dynmat.x

[xirainbow]

Dear Professor Stefano Baroni:
Thank you for you exhaustive explanation. I am deeply benefited from it.
This basic question has been troubling my mind for many years.
Thank you very much ??

On Sun, May 1, 2011 at 6:08 PM, Stefano Baroni  wrote:

> Eyvaz, All: I beg to differ, here, though it's probably a matter of
> terminology.
>
> On Apr 29, 2011, at 9:41 AM, Eyvaz Isaev wrote:
>
>  Dear Wang,
>
> Let me reiterate: LO-TO splitting takes place ONLY at the Gamma point.
>
>
> I would rather say a LO-TO splitting ALWAYS occur at q/=0 in any crystal,
> simply because there is no reason why it should not. (if two modes are not
> related by symmetry, their frequencies usually differ, and LO and TO modes
> are NOT related by any symmetry operations. Weird things only occur at q=0
> in polar materials. See below ...
>
>  >For cubic crystals splitting is equal in all directions.
> So, for non-cubic LO-TO splitting  also occurs and the splitting is
> different for different directions. That is
> why one can see a discontinuity near the Gamma point in phonon dispersion
> relations.
>
>
> the situation is even a bit more messy (also, see below ...)
>
> >When q is zero, there is no longitude and transverse mode.
> Really? How about optical modes? Did you pay attention to "O"?
>
>
> Strictly speaking, I believe Wang is right. At q=0 it makes no sense to
> speak about longitudinal or transverse modes, simply because it makes no
> sense to say that the polarization of the mode is parallel (L) or
> perpendicular (T) to a vector (q) whose norm is 0 (q=0). The problem is, in
> a polar *and infinite* crystal q=0 modes do not exist (!!!), because the
> infinite range of the Coulomb interaction makes the dynamical matrix
> ill-defined at q=0. So, in this case, not only is it impossible to assign a
> transverse or longitudinal character to a lattice vibration (which would be
> true for non polar materials as well), but the very concept of lattice
> vibration breaks down. What one actually calculates when one calculates the
> LO or TO modes is the q->0 limit of finite-q modes. When the system is non
> polar, this limit is well defined and independent of the relative
> orientation of the polarization and wavevector. In polar materials, instead,
> this limit depends on this relative orientation, hence it is not defined in
> the q-> limit. So, the L or T character of a lattice vibration is NOT a
> property of the vibrations at q=0, but only in the q->0 limit.
>
> So far, so good, if at small but finite q the polarization of normal modes
> can be chosen to be parallel or perpendicular to the direction of
> propagation of the vibration. This is indeed the case for phonons
> propagating along high-simmetry lines in cubic materials. For low-simmetry
> lines in cubic materials, or any line in non-cubic materials, this may not
> even be the case and lattice vibrations in the q->0 limit in general are not
> longitudinal nor transverse. What continues to be true is that the q->0
> limit is that vibrational frequencies will depend on the direction of
> propagation of the phonon, so that, strictly speaking, lattice-perdiodic
> vibrations are not well defined ...
>
> Hope to have clarified a bit the (admittedly messy) situation ...
>
> Stefano B
>
>  ---
> Stefano Baroni - SISSA  &  DEMOCRITOS National Simulation Center - Trieste
> http://stefano.baroni.me [+39] 040 3787 406 (tel) -528 (fax) /
> stefanobaroni (skype)
>
> La morale est une logique de l'action comme la logique est une morale de la
> pens?e - Jean Piaget
>
> Please, if possible, don't  send me MS Word or PowerPoint attachments
> Why? See:  http://www.gnu.org/philosophy/no-word-attachments.html
>
>
>
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
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>


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Hui Wang
School of physics, Fudan University, Shanghai, China
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[Pw_forum] bulk projected band structure

[xirainbow]

Dear Ming:
I have less experience in bulk projected band structure.
I think you can do scf calculation with less k-points in three directions.
Then switch to nscf calculation for dense k-points in z-direction, similar
with dos calculation.

On Sat, Apr 30, 2011 at 11:34 AM, wenmei ming  wrote:

> Dear all,
>
> I'm going to plot bulk projected band structure on a 2D BZ. I'm
> guessing(take x-y plane 2D for example) for every k point in xy plane (K_x,
> k_y, 0.0) I have to calculate all other energies with different k_z. By this
> way the final energy band structure with K index only on xy plane is
> so-called bulk projected band structure. But one problem for this I need to
> specify too much k-points, so I am wondering if there is a more efficient
> way to do this? Can someone share your experience in this?
>
> Thanks so much in advance.
>
> Jack Ming
>
> ___
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>


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School of physics, Fudan University, Shanghai, China
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[Pw_forum] LO-TO splitting in dynmat.x

[xirainbow]

Dear Professor Stefano:
You mean when q->0, the polar phonon is described by Huang-equation?
If so, I know the answer:)
Thank you very much;)

On Fri, Apr 29, 2011 at 7:16 PM, Stefano de Gironcoli wrote:

>  if you really want to know what happens close to gamma... look for the
> theory of polaritons.
> also of interest can be to look for derivation of Lyddane-Sachs-Teller
> relationship.
> stefano
>
>
>
> On 04/29/2011 12:23 PM, xirainbow wrote:
>
> Dear Professor Eyvaz:
> Thank you very much for your instruction:)
>
>
>  When q is zero, there is no longitude and transverse mode.
> Really? How about optical modes? Did you pay attention to "O"?
>
>
>  I do not express myself clearly.
> When q=0,  q has no direction. Therefore, optical modes can not be
> classified into longitude or transverse ones. As a result, at q=0,  these
> optical phonon should be still degenerate( LO=TO ).
>
>
>
>
>  Bests,
> Eyvaz.
>
> ---
> Prof. Eyvaz Isaev,
> Department of Physics, Chemistry, and Biology (IFM), Linkoping University,
> Sweden
> Theoretical Physics Department, Moscow State Institute of Steel & Alloys,
> Russia,isaev at ifm.liu.se, eyvaz_isaev at yahoo.com
>
>
> --
> *From:* xirainbow  
> *To:* PWSCF Forum  
> *Sent:* Fri, April 29, 2011 9:30:31 AM
>
> *Subject:* Re: [Pw_forum] LO-TO splitting in dynmat.x
>
> Dear Sonu Kumar
> What you said is reasonable;)
>
> I have two little questions.
> One:
> Does LO-TO splitting must disappear at the boundary of Brillouin zone?
>
> Two:
> I can understand the LO-TO splitting near Gamma point.
> However, at Gamma point(not  near Gamma point), q=0. When q is zero, there
> is no longitude and transverse mode. Why are there LO-TO splitting at Gamma
> point?
>
> Thanks:)
>
>
>
> On Fri, Apr 29, 2011 at 1:21 PM, sonu kumar <1009ukumar at gmail.com> 
> <1009ukumar at gmail.com> wrote:
>
>
>  Dear All QE users,
>
> i am sorry again, as i havn't corrected the subject title.
>
>
> (2) only cubic crystals has LO and TO braches.
>
>   crystals ( having considerable values of macroscopic dielectric constant [
> i suppose
> epsilon infinity] and born effective charges, as pointed  out by Prof.
> Eyvaz Isaev) with low symmetry can, also, have LO-TO splitting. But this can
> be  different in different symmetry directions, so one has to search all
> symmetry directions for this splitting.
>
> For cubic crystals splitting is equal in all directions.
>
> with regards,
>
> --
> Sonu Kumar
>
> Phd Student
> Physics Department
> Indian Institute of Technology
> Delhi-110016, India
> web:-http://www.iitd.ac.in/
>
> ___
> Pw_forum mailing listPw_forum at 
> pwscf.orghttp://www.democritos.it/mailman/listinfo/pw_forum
>
>  --
> 
> Hui Wang
> School of physics, Fudan University, Shanghai, China
>
> ___
> Pw_forum mailing listPw_forum at 
> pwscf.orghttp://www.democritos.it/mailman/listinfo/pw_forum
>
>
> ___
> Pw_forum mailing listPw_forum at 
> pwscf.orghttp://www.democritos.it/mailman/listinfo/pw_forum
>
>
>
> ___
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> Pw_forum at pwscf.org
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>


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Hui Wang
School of physics, Fudan University, Shanghai, China
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[Pw_forum] LO-TO splitting in dynmat.x

[xirainbow]

Dear Huang:
Thanks very much for your valuable discussion.
I are reading your mentioned paper:)

On Fri, Apr 29, 2011 at 5:20 PM, lfhuang  wrote:

>  Dear Wang, H:
> > Suppose a uniaxial crystal(no cubic): c>a=b. Suppose there is a
> > double-degenerate polar E_u mode, in which all atoms move in the a-b
> plane.
> > If the wavevector around Gamma point is in the a-b plane, the degenerate
> E
> > mode will split into LO and TO mode.
> > Am I right?
>
> It is probable for some ionic crystals, but still depends.
> Maybe the Equ. 98 (nonanalytic part of the dynamical matrix) in Rev. Mod.
> Phys. 73, 515 (2001) by prof. S. Baroni etc. and the related parts in the
> book "Dynamical Theory of Crystal Lattices" by M. Born & K. Huang can give
> you much information if these things are important/interesting to you.
>
> In addition, is the method "finite difference" you mentioned exactly the
> "frozen phonon" or "small displacement" method? If so, the treatment like
> that in PWSCF should be good to obtain a satisfied LO/TO splitting, although
> honestly I haven't done this in the "frozen phonon" method. Some people
> propose other methods, like using a prolonged supercell, which I think,
> could not fully describe the long-range dipolar interaction, because of its
> long-range character (as prof. Stefano de Gironcoli said ~1/R^3).
>
> Best Wishes!
> Yours Sincerely
> L. F. Huang
> --
> ==
> L.F.Huang(???) DFT and phonon physics
> ==
> Add: Research Laboratory for Computational Materials Sciences,
> Instutue of Solid State Physics,the Chinese Academy of Sciences,
> P.O.Box 1129, Hefei 230031, P.R.China
> Tel: 86-551-5591464-326(office)
> Fax: 86-551-5591434
> Our group: http://theory.issp.ac.cn
> ==
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
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>


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Hui Wang
School of physics, Fudan University, Shanghai, China
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[Pw_forum] LO-TO splitting in dynmat.x

[xirainbow]

Dear Professor Eyvaz:
Thank you very much for your instruction:)

>When q is zero, there is no longitude and transverse mode.
> Really? How about optical modes? Did you pay attention to "O"?
>
I do not express myself clearly.
When q=0,  q has no direction. Therefore, optical modes can not be
classified into longitude or transverse ones. As a result, at q=0,  these
optical phonon should be still degenerate( LO=TO ).



> Bests,
> Eyvaz.
>
> ---
> Prof. Eyvaz Isaev,
> Department of Physics, Chemistry, and Biology (IFM), Linkoping University,
> Sweden
> Theoretical Physics Department, Moscow State Institute of Steel & Alloys,
> Russia,
> isaev at ifm.liu.se, eyvaz_isaev at yahoo.com
>
>
> --
> *From:* xirainbow 
> *To:* PWSCF Forum 
> *Sent:* Fri, April 29, 2011 9:30:31 AM
>
> *Subject:* Re: [Pw_forum] LO-TO splitting in dynmat.x
>
> Dear Sonu Kumar
> What you said is reasonable;)
>
> I have two little questions.
> One:
> Does LO-TO splitting must disappear at the boundary of Brillouin zone?
>
> Two:
> I can understand the LO-TO splitting near Gamma point.
> However, at Gamma point(not  near Gamma point), q=0. When q is zero, there
> is no longitude and transverse mode. Why are there LO-TO splitting at Gamma
> point?
>
> Thanks:)
>
>
>
> On Fri, Apr 29, 2011 at 1:21 PM, sonu kumar <1009ukumar at gmail.com> wrote:
>
>> Dear All QE users,
>>
>> i am sorry again, as i havn't corrected the subject title.
>>
>>
>> (2) only cubic crystals has LO and TO braches.
>>>
>>
>> crystals ( having considerable values of macroscopic dielectric constant [
>> i suppose
>> epsilon infinity] and born effective charges, as pointed  out by Prof.
>> Eyvaz Isaev) with low symmetry can, also, have LO-TO splitting. But this can
>> be  different in different symmetry directions, so one has to search all
>> symmetry directions for this splitting.
>>
>> For cubic crystals splitting is equal in all directions.
>>
>> with regards,
>>
>> --
>> Sonu Kumar
>>
>> Phd Student
>> Physics Department
>> Indian Institute of Technology
>> Delhi-110016, India
>> web:-http://www.iitd.ac.in/
>>
>> ___
>> Pw_forum mailing list
>> Pw_forum at pwscf.org
>> http://www.democritos.it/mailman/listinfo/pw_forum
>>
>>
>
>
> --
> 
> Hui Wang
> School of physics, Fudan University, Shanghai, China
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>
>


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School of physics, Fudan University, Shanghai, China
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[Pw_forum] LO-TO splitting in dynmat.x

[xirainbow]

Dear Professor Stefano:
Thanks very much for your patient instruction.
I will read your mentioned paper carefully.
And now, I imagine that the phonon dispersion near Gamma point may look
like:

^ Frequency
 |
 |
*@* |*@****LO*
 |
 |
*   **$**@$   TO*
 |
  <---|->
  Gamma wavevector near Gamma

When q->0, there is  LO-TO splitting.
When q=0,  q has no direction. Therefore, optical modes can not be
classified into longitude or transverse ones. As a result, at q=0,  *$*=*@.*
However, there is not infinite crystal; and electric-static interaction
always occurs for finite crystal.
Therefore, in experiment, LO-TO splitting exists at the q=0.

On Fri, Apr 29, 2011 at 3:16 PM, Stefano de Gironcoli wrote:

>  the electristatic interaction at the origin of LO-TO splitting is always
> present...
>
> for any q<>0 (even very small) it is included in the calculation.
>
> in the limit of q->0 in non-metallic systems it gives origin to a non
> analytic behavior that must be calculate separately.
>
> If you want to Fourier interpolate the phonon dispersions calculated on a
> regular grid of q-points
> you are in trouble because non analyticity of the phonon dispersion implyes
> long-range (1/R^3) interatomic force constants and so you need to
>
> 1) evaluate Z* and epsilon_infty in the limit of q->0 that determine the
> non-analyticity
> 2) remove from dynamical matrix in every q point in you grid an
> electrostatic model that gives the correct non-analyticity for q->0 and is
> smooth elsewhere
> 3) Fourier interpolate  the modified (hopefully short-range) dynamical
> matrices
> 4) add back the model in any q-point you want to study.
>
> This is what the sequence ph.x -> q2r.x -> matdyn.x does (in example06 for
> instance)
>
> thete is some discussion of these issues in Review of Modern Physics 73,
> 515 (2001) and in Phys Rev 43, 7231 (1991)
>
> stefano
>
> On 04/29/2011 05:05 AM, xirainbow wrote:
>
> Dear Eyvaz:
> Thank you very much;)
>
>
>  Is there LO-TO splitting far away from Gamma point?
> No.
>
>
>  Does LO-TO splitting must disappear at the boundary of Brillouin zone?
>
>
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.orghttp://www.democritos.it/mailman/listinfo/pw_forum
>
>
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>
>


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[Pw_forum] LO-TO splitting in dynmat.x

[xirainbow]

Dear Sonu Kumar
What you said is reasonable;)

I have two little questions.
One:
Does LO-TO splitting must disappear at the boundary of Brillouin zone?

Two:
I can understand the LO-TO splitting near Gamma point.
However, at Gamma point(not  near Gamma point), q=0. When q is zero, there
is no longitude and transverse mode. Why are there LO-TO splitting at Gamma
point?

Thanks:)



On Fri, Apr 29, 2011 at 1:21 PM, sonu kumar <1009ukumar at gmail.com> wrote:

> Dear All QE users,
>
> i am sorry again, as i havn't corrected the subject title.
>
>
> (2) only cubic crystals has LO and TO braches.
>>
>
> crystals ( having considerable values of macroscopic dielectric constant [
> i suppose
> epsilon infinity] and born effective charges, as pointed  out by Prof.
> Eyvaz Isaev) with low symmetry can, also, have LO-TO splitting. But this can
> be  different in different symmetry directions, so one has to search all
> symmetry directions for this splitting.
>
> For cubic crystals splitting is equal in all directions.
>
> with regards,
>
> --
> Sonu Kumar
>
> Phd Student
> Physics Department
> Indian Institute of Technology
> Delhi-110016, India
> web:-http://www.iitd.ac.in/
>
> ___
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>
>


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[Pw_forum] LO-TO splitting in dynmat.x

[xirainbow]

Dear Huang:

This could depend on the definition of "LO-TO splitting", which I meant "the
> reduction of the LO-TO degeneracy".
>

I still have another question  ??
 Suppose a uniaxial crystal(no cubic): c>a=b. Suppose there is a
double-degenerate polar E_u mode, in which all atoms move in the a-b plane.
If the wavevector around Gamma point is in the a-b plane, the degenerate E
mode will split into LO and TO mode.
Am I right?

-- 

Hui Wang
School of physics, Fudan University, Shanghai, China
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[Pw_forum] LO-TO splitting in dynmat.x

[xirainbow]

Dear Huang:
I think you are right;)
Thanks a lot :P



On Fri, Apr 29, 2011 at 11:50 AM, lfhuang  wrote:

>  Dear Wang:
>
> > LO-TO splitting always exists in Brillouin zone, but two points are worth
>
> > > noting:
> > >
> > I do not think so. I do not find any LO-TO splitting at the X and R point
> of
> > Brillouin zone of cubic.
>
> This could depend on the definition of "LO-TO splitting", which I meant
> "the reduction of the LO-TO degeneracy".
> If it is defined to be the splitting due to the long-range electric force
> on LO, it will disappear in BZ zone.
>
> Best Wishes!
> Yours Sincerely
> L. F. Huang
> --
> ==
> L.F.Huang(???) DFT and phonon physics
> ==
> Add: Research Laboratory for Computational Materials Sciences,
> Instutue of Solid State Physics,the Chinese Academy of Sciences,
> P.O.Box 1129, Hefei 230031, P.R.China
> Tel: 86-551-5591464-326(office)
> Fax: 86-551-5591434
> Our group: http://theory.issp.ac.cn
> ==
>
> ___
> Pw_forum mailing list
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>


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[Pw_forum] LO-TO splitting in dynmat.x

[xirainbow]

Dear Eyvaz:
Thank you very much;)

> Is there LO-TO splitting far away from Gamma point?
> No.
>

Does LO-TO splitting must disappear at the boundary of Brillouin zone?

-- 

Hui Wang
School of physics, Fudan University, Shanghai, China
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[Pw_forum] LO-TO splitting in dynmat.x

[xirainbow]

Dear Huang:
Thanks very much for your help:)

 LO-TO splitting always exists in Brillouin zone, but two points are worth
> noting:
>
I do not think so. I do not find any LO-TO splitting at the X and R point of
Brillouin zone of cubic.
Because I use finite difference method, I do not know LO-TO splitting
persists at other part.


> (2) only cubic crystals has LO and TO braches.
>
The LO-TO splitting exists also in uniaxial crystal(direction dispersion in
Raman).
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Hui Wang
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[Pw_forum] LO-TO splitting in dynmat.x

[xirainbow]

Dear all:
Is there LO-TO splitting far away from Gamma point?
How large is the influence range of LO-TO splitting in Brillouin zone? One
hundred percent?
Thanks in advance;)



-- 

Hui Wang
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[Pw_forum] radius of the sphere to calculate the projected density of states

[xirainbow]

Dear Gianluca Giovannetti:
I hope this would give you some help:)
http://www.democritos.it/pipermail/pw_forum/2011-April/019891.html


On Tue, Apr 19, 2011 at 2:15 PM, Gianluca Giovannetti <
gianluca.giovannetti at gmail.com> wrote:

> Dear All,
>
> i`m calculating the projected density of states of some material.
>
> this should be done integrating within a sphere.
>
> can i change the radius of such sphere in PW?
>
> i thank you in advance.
>
> cheers,
>
> Gianluca Giovannetti
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
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>
>


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[Pw_forum] fermi energy from scf vs nscf calculations

[xirainbow]

Dear Farzad Molani:
Is the difference big?
Maybe you do not do the convergence test about k-mesh or encut. If all
parameters are converged, nscf will give the same fermi energy with scf.

On Tue, Apr 12, 2011 at 4:34 PM, Farzad Molani  wrote:

> Hello pwscf users,
> I want to study my system by DOS calculations, I have a question about my
> result. Fermi energy  In SCF calculation is defferent from nscf calculation.
> which of them is correct?
> with the best regards.
>
> Farzad Molani,
> Ph.D Student,
> Department of Theoretical Physical Chemistry,
> K. N. Toosi University of Technology,
> Tehran, Iran.
> Tel.: 009891 4442 3308
> Tel.: 009821 2306 4280
> Fax: 009821 2285 3650
> Web: http://www.chem.kntu.ac.ir/~sjalili:/
>
> ___
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>
>


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[Pw_forum] Born effective charge

[xirainbow]

Dear Paolo Giannozzi:
Thank you  very much for your correction:)
I couldn't imagine the physical meaning of imaginary part. I hope I can
understand it after reading the paper (PRB62,3735).

On Thu, Apr 7, 2011 at 4:35 PM, Paolo Giannozzi wrote:

>
> On Apr 7, 2011, at 9:40 , xirainbow wrote:
>
> > Based on the definition of Born effective charge, it is a  "real
> > symmetric matrix?.
>
> real, but not symmetric, in general
>
> P.
> ---
> Paolo Giannozzi, Dept of Chemistry&Physics&Environment,
> Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
> Phone +39-0432-558216, fax +39-0432-558222
>
>
>
>
> ___
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>



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[Pw_forum] Born effective charge

[xirainbow]

Dear M. Abbasnejad:



Trying to calculate the born effective charges of my case, the obtained
> diagonalized principal values of effective charge tensor have imaginary
> part.

Is the  ?diagonalized principal values? is calculated by yourself , or it is
written in the output file?
If it is the first occasion, I think it is your fault.
Based on the definition of Born effective charge, it is a  "*real symmetric
matrix*?.
The eigen value of real symmetric matrix should not have imaginary part.



-- 

Hui Wang
School of physics, Fudan University, Shanghai, China
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[Pw_forum] Calculational equation of PDOS

[xirainbow]

Dear Professor Gabriele Sclauzero:
After reading your thesis, I examine the Si.pbe-rrkj.UPF and find that there
is not d orbital for Si.

This the date in Si.pbe-rrkj.UPF:
__
23 Number of Wavefunctions, Number of Projectors
 Wavefunctions nl  l   occ
   3S  0  2.00
   3P  1  2.00

10 BetaL
20 BetaL
31 BetaL
?

However, in the table II of Phys. Rev. B 26, 4199 (1982,Pseudopotentials
that work From H to Pu), the configurations used to derive pseudopotential
always have d orbital for all kinds of atoms, including H.

Does this sugguest that there is no pseudopotential for d orbital in
Si.pbe-rrkj.UPF?
Does this sugguest that the pdos of d orbital is always zero based on
Si.pbe-rrkj.UPF?
I am a little confused:(

On Fri, Apr 1, 2011 at 4:04 PM, Gabriele Sclauzero wrote:

>
> Il giorno 01/apr/2011, alle ore 07.09, xirainbow ha scritto:
>
> Dear Professor
>
>
> Thanks for upgrading my position :D
>
> Gabriele Sclauzero:
> Thank you for your prompt help.
> I read your thesis and benefit a lot from it:)
>
>
> I'm glad of that, at least all the efforts I put in writing it could be
> useful to someone (thanks also to those who corrected the manuscript...)
>
>
> Cheers,
>
>
> GS
>
> Thanks again:P
>
>
> On Thu, Mar 31, 2011 at 7:58 PM, Gabriele Sclauzero  sissa.it>wrote:
>
>> Dear Wang,
>>
>> I remember that I put down a formula for that in my PhD thesis (
>> http://www.sissa.it/cm/thesis/2010/SclauzeroG_PhDthesis.pdf), if this may
>> help you (see eq. 2.74 at page 58). I'm sure you could find it in many other
>> places, though.
>>
>>I believe there's no such thing as the Rcut you write in your formula
>> below. As you say, the atomic wavefunctions are built from the radial part
>> R_nl(r), which is taken from the pseudopotential file, and the spherical
>> harmonics. However you should not forget that there is also structure factor
>> which comes from the translation of the nucleus from the origin.
>> The integral is done in reciprocal space for each k-point, hence a
>> k-dependence is added to the atomic wavefunction when transforming it to the
>> G-basis (have a look in PW/atomic_wfc.f90).
>>
>> The following paper might also be useful to you:
>>
>> Solid State Communications, Vol. 95, No. 10, pp. 685-690, 1995
>>
>>
>>
>>
>> HTH
>>
>> GS
>>
>> Il giorno 31/mar/2011, alle ore 12.27, xirainbow ha scritto:
>>
>> Dear all:
>>   I want to know the calculational equation of partial density of
>> state(PDOS) in QE.
>>   I could not find the equation on any paper. I think it may be:
>> \int_0^{Rcut}  \Psi(\vec r)*R_n(r)*Y_{lm}(\theta,\phi)*r^2 dr d\theta
>> d\phi.
>> where the Psi(\vec r) is the KS wave function of solid.
>> Y_{lm}(\theta,\phi) is the spherical harmonics. R_n(r) is the the radial
>> wave function of a isolated atom.
>> If I was right, what is the formation of R_n(r)?
>>
>> Thanks in advance:)
>>
>> --
>> 
>> Hui Wang
>> School of physics, Fudan University, Shanghai, China
>> ___
>> Pw_forum mailing list
>> Pw_forum at pwscf.org
>> http://www.democritos.it/mailman/listinfo/pw_forum
>>
>>
>>
>> ? Gabriele Sclauzero, EPFL SB ITP CSEA
>> *   PH H2 462, Station 3, CH-1015 Lausanne*
>>
>>
>> ___
>> Pw_forum mailing list
>> Pw_forum at pwscf.org
>> http://www.democritos.it/mailman/listinfo/pw_forum
>>
>>
>
>
> --
> 
> Hui Wang
> School of physics, Fudan University, Shanghai, China
>  ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>
>
>
> ? Gabriele Sclauzero, EPFL SB ITP CSEA
> *   PH H2 462, Station 3, CH-1015 Lausanne*
>
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>
>


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[Pw_forum] Calculational equation of PDOS

[xirainbow]

Dear Professor Gabriele Sclauzero:
Thank you for your prompt help.
I read your thesis and benefit a lot from it:)
Thanks again:P


On Thu, Mar 31, 2011 at 7:58 PM, Gabriele Sclauzero wrote:

> Dear Wang,
>
> I remember that I put down a formula for that in my PhD thesis (
> http://www.sissa.it/cm/thesis/2010/SclauzeroG_PhDthesis.pdf), if this may
> help you (see eq. 2.74 at page 58). I'm sure you could find it in many other
> places, though.
>
>I believe there's no such thing as the Rcut you write in your formula
> below. As you say, the atomic wavefunctions are built from the radial part
> R_nl(r), which is taken from the pseudopotential file, and the spherical
> harmonics. However you should not forget that there is also structure factor
> which comes from the translation of the nucleus from the origin.
> The integral is done in reciprocal space for each k-point, hence a
> k-dependence is added to the atomic wavefunction when transforming it to the
> G-basis (have a look in PW/atomic_wfc.f90).
>
> The following paper might also be useful to you:
>
> Solid State Communications, Vol. 95, No. 10, pp. 685-690, 1995
>
>
>
>
> HTH
>
> GS
>
> Il giorno 31/mar/2011, alle ore 12.27, xirainbow ha scritto:
>
> Dear all:
>   I want to know the calculational equation of partial density of
> state(PDOS) in QE.
>   I could not find the equation on any paper. I think it may be:
> \int_0^{Rcut}  \Psi(\vec r)*R_n(r)*Y_{lm}(\theta,\phi)*r^2 dr d\theta
> d\phi.
> where the Psi(\vec r) is the KS wave function of solid. Y_{lm}(\theta,\phi)
> is the spherical harmonics. R_n(r) is the the radial wave function of a
> isolated atom.
> If I was right, what is the formation of R_n(r)?
>
> Thanks in advance:)
>
> --
> 
> Hui Wang
> School of physics, Fudan University, Shanghai, China
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>
>
>
> ? Gabriele Sclauzero, EPFL SB ITP CSEA
> *   PH H2 462, Station 3, CH-1015 Lausanne*
>
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
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>
>


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[Pw_forum] Valence state identification

[xirainbow]

Dear Geng:
First of all,  Professor Nicola Marzari answered your question the day
before yesterday.
>The oxidation state is a phenomenological concept, and not well defined.
>The closest physical thing is the Born effective charge.
>The number of valence electrons for any pseudopotential is given
>by Z valence, in the header of that pseudopotential file.
>   nicola

Do not continue to ask the same question. It is a wast of your time and
others!

Secondly,I do not think you can get Ba2+ or O O2-.
The valence state your mentioned is static charge.
However, static charge is not a well-defined quality, as all valence
electrons belong to the crystal, not atoms.
Maybe Mulliken charge is what you want, but I do not think QE can give it.
But QE can give Bader and Lowdin analysis, referring to
http://www.democritos.it/pipermail/pw_forum/2010-June/017204.html
http://www.democritos.it/pipermail/pw_forum/2010-May/016847.html

Alternatively, you can get dynamical charge with QE.For dynamical charge, Ba
maybe is smaller than 2 and O bigger than 2.


On Fri, Apr 1, 2011 at 11:32 AM, Liwei Geng  wrote:

>  Dear all,
>
>
>
> I've done the scf calculation using atom pseudopotential files, but I can't
> know their valence state. Could you tell me how to identify the valence
> state of each ion in BaTiO3 using QE? Say, how can I know that the Ba is
> Ba2+ or O is O2-?
>
>
>
> Thanks,
>
> Liwei
>
> ___
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> Pw_forum at pwscf.org
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>
>


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[Pw_forum] Calculational equation of PDOS

[xirainbow]

Dear all:
  I want to know the calculational equation of partial density of
state(PDOS) in QE.
  I could not find the equation on any paper. I think it may be:
\int_0^{Rcut}  \Psi(\vec r)*R_n(r)*Y_{lm}(\theta,\phi)*r^2 dr d\theta d\phi.
where the Psi(\vec r) is the KS wave function of solid. Y_{lm}(\theta,\phi)
is the spherical harmonics. R_n(r) is the the radial wave function of a
isolated atom.
   If I was right, what is the formation of R_n(r)?

Thanks in advance:)

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School of physics, Fudan University, Shanghai, China
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[Pw_forum] Help for Calculating Organic Crystal Band Structure

[xirainbow]

I am fully convienced that pwscf can deal with organic crystal. But, I
have no example.

On 2011-03-23, ANUP THOMAS  wrote:
> Dear All
>
> I, Anup Thomas, a novice in this field of solid state structure
> simulation. I would like to perform band structure calculations for some
> organic crystals. In my limited knowledge i could not find any one using
> Pwscf for organic crstals band structure. Would any one please let me know
> Pwscf can simulate the data?
>
>   I will appreciate very much if you can give me more advices.
>
>
>
> --
> Regards
>
> Anup Thomas
> SRF 7123
> Computational Chemistry Lab of I and PC Division
> Indian Institute of Chemical Technology
> Hyderabad 57
> India
>
>
> "Praise the Lord, all you nations; extol him, all you peoples.
> For great is his love toward us, and the faithfulness of the Lord endures
> forever.
> Praise the Lord"
>


-- 

Hui Wang
School of physics, Fudan University, Shanghai, China

[Pw_forum] graphite cell optimization failed

[xirainbow]

*Dear Eric.*
*I met the same problem with you 3 years ago. But I did not fix it. I think
it is related with the functional, which does not include dynamical dipole
interaction.*
*
*
*There are some discussion about the vander Waals interaction in PWSCF. I
hope it will help you:)*
*http://www.democritos.it/pipermail/pw_forum/2010-November/018516.html*
*
*
*On Thu, Mar 24, 2011 at 12:33 AM, Eric Germaneau wrote:
*
>
> * Dear all,
>
> I'm trying to optimize unit cell parameter of graphite.
> The problem is the c axis gets too long.
> Starting from published data my initial parameters are a=4.59203 Bohr and
> c=12.513 Bohr.
> The final values are 4.664 and 15.829 respectively.
> I need someone to explain to me what I did wrong, I've attached my input
> file.
> That's a basic calculation so it's very frustrating to not make it done.
> I thank you in advance,
>
> Eric.
>
> *
> *--
> * * Be the change you wish to see in the world
>   ? Mahatma Gandhi ?
>
> Dr. ?ric Germaneau 
>
> College of Physical Sciences
> Graduate University of Chinese Academy of Sciences
> Yuquan Road 19A
> Beijing 100049
> China
>
>   Please consider the environment before printing this email.
> Consid?rez svp l'environnement avant d'imprimer cet email.  *
>  *
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>
> *

*


-- 

Hui Wang
School of physics, Fudan University, Shanghai, China*
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