Re: [Pw_forum] Raman

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

Re: [Pw_forum] Raman and IR spectra

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

Re: [Pw_forum] band gap at Gamma point in primitive cell different from the band gap at Gamma point in conventional cell

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

[Pw_forum] ignoring the antiferromagnetic order in the symmetry analysis of phonons

> 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?

> 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

> 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

> 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

[Pw_forum] info Raman spectrum

> - 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.

[Pw_forum] phonon frequencies ....

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

[Pw_forum] Regarding LA-TA modes

> 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: >

[Pw_forum] Band structure of graphene

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

[Pw_forum] q-point mesh in PHonon

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

[Pw_forum] supercell and k-point

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

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

> 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

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

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

[Pw_forum] regarding thermal conductivity

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 > >

[Pw_forum] curie temperature of double perovskite

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

[Pw_forum] 3 additional frequencies (6 total) when only displace one atom in the PH.x calculation

> 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.

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

> 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

[Pw_forum] choosing k-point in slab calculations

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

[Pw_forum] STO Structure breaking - reg.,

> 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. >

[Pw_forum] unit of phonon dos

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.",

[Pw_forum] Magnetism

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

[Pw_forum] phonon calculation

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,

[Pw_forum] regarding born-effective charge

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

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

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

[Pw_forum] SPIN POLARIZATION CALCULATIONS

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

[Pw_forum] ibrav for orthorhombic space group

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.

[Pw_forum] K points: phonon dispersion

I hope it works:) 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

[Pw_forum] ELASTIC code with Quantum Espresso

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

[Pw_forum] not converge after 100 itration

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

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

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

[Pw_forum] probleme with pdos

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

[Pw_forum] Magnetic Field

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

[Pw_forum] What does total energy contain?

" 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

[Pw_forum] What does total energy contain?

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

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

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 (nkxir

[Pw_forum] CNT unit cell vectors

> 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

[Pw_forum] CNT unit cell vectors

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

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

; 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 >>

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

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

[Pw_forum] vc-relax

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. >

[Pw_forum] Real displacements from the complex eigenvectors

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

[Pw_forum] phonon calculation

stem 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

[Pw_forum] phonon calculation

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

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

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

[Pw_forum] "Raman activities" do not converge

ot;? 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_forum] "Raman activities" do not converge

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 >

[Pw_forum] "Raman activities" do not converge

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 activ

[Pw_forum] "Raman activities" do not converge

t; > 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

[Pw_forum] "Raman activities" do not converge

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)

[Pw_forum] Raman result wrong, intensity at 0.0 cm-1 is not zero.

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

[Pw_forum] ”wrong representation“ from ”set_irr_sym“

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

[Pw_forum] gap width in dos and band

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

[Pw_forum] Charge density at any k-point in the Brillouin zone

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

[Pw_forum] Electro-optic tensor contribution

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

[Pw_forum] Slip in comments of dynmat.f90

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

[Pw_forum] Not convergence of the scf in phonon calculation

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,

[Pw_forum] murnaghan : bct

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

[Pw_forum] How to set "electrons" parameters in ph.x ?

t 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: &g

[Pw_forum] How to set "electrons" parameters in ph.x ?

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

[Pw_forum] Bug in matdyn.f90

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)

[Pw_forum] Non zero "Effective Charges" of Silicon in "example02"

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.

[Pw_forum] A little energy gap (~ 0.2 eV) for graphene

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

[Pw_forum] How to realize the parallel calculation?

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

[Pw_forum] energy/force/stress obtained from scf versus vc-relax

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. >

[Pw_forum] LO-TO splitting

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:)

[Pw_forum] Can pwscf calculate the structure of charged slab ?

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

[Pw_forum] charge density

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

[Pw_forum] Doubt in band plot

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

[Pw_forum] the unit of DOS

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

[Pw_forum] smearing

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

[Pw_forum] Graphene Nanoribbon

phene, 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 ribbon

[Pw_forum] Graphene Nanoribbon

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

[Pw_forum] LO-TO splitting in dynmat.x

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

[Pw_forum] bulk projected band structure

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: >

[Pw_forum] LO-TO splitting in dynmat.x

t; 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, the

[Pw_forum] LO-TO splitting in dynmat.x

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

[Pw_forum] LO-TO splitting in dynmat.x

emistry, 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:* PWS

[Pw_forum] LO-TO splitting in dynmat.x

2r.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 ver

[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

[Pw_forum] LO-TO splitting in dynmat.x

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

[Pw_forum] LO-TO splitting in dynmat.x

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

[Pw_forum] LO-TO splitting in dynmat.x

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 -- next part

[Pw_forum] LO-TO splitting in dynmat.x

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

[Pw_forum] LO-TO splitting in dynmat.x

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 School of physics, Fudan University, Shanghai, China --

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

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>

[Pw_forum] fermi energy from scf vs nscf calculations

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

[Pw_forum] Born effective charge

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

[Pw_forum] Born effective charge

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

[Pw_forum] Calculational equation of PDOS

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 y

[Pw_forum] Calculational equation of PDOS

> > > > > 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.

[Pw_forum] Valence state identification

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

[Pw_forum] Calculational equation of PDOS

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

[Pw_forum] Help for Calculating Organic Crystal Band Structure

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

[Pw_forum] graphene's band gap

Dear Eric: The occupied and unoccupied bands touch each other only at M point(or K point, I forget it). You must include this point in you k-mesh. Furthermore, if you include spin-orbital coupling, the band gap will be opened at this point. On Thu, Mar 10, 2011 at 1:30 AM, Eric Germaneau wrote:

[Pw_forum] Fermi energy Calculation

Dear *Meysam Pazoki*: Fermi energy indicate that:Below it, all the states is occupied by electrons, whereas no electron is above it. In my view, Fermi energy can below or above zero. And, in pseudopotential method, the absolute value of fermi energy has no physical meaning. If i am wrong, please

[Pw_forum] help with /examples/example03

Dear Amin: > 1 I understand that the task of this example is to find the minimum > geometry. but how does it decide to to put the molecule in a box of side 12 > bohr? where does 12 come from? > You have to do a convergence test to decide the length of box. In my experience, keeping the nearest

[Pw_forum] Wrong effective charges in AFM insulator using "zue"

Dear Professor Paolo: Thank you for your valuable instruction:) Why is it almost impossilbe to obtain zero for tranlational modes from the linear response calculation? Does finite displacement method (frozen phonon) can get zero? Does it relate with spatial discretization? I am interested in

[Pw_forum] “Effective charge" of antiferromagnetic state

Dear all: I met a problem with *"effective charge" of antiferromagnetic state* in espresso-4.2.1. I have antiferromagnetic CaMnO3 with FCC(10 atoms in primitive unit cell), and these two Mn atoms are *the same except antiparallel spin.* The calculated effective charge of Mn1 is *14.1*, but Mn2 is

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