[Pw_forum] something strange in rutile and anatase calculation

[vega]

Dear sir,

thank you for your so kindly explanation. I also have some questions about 
your article.

> As you can see we considered three FeH phases (FCC, HCP, and DHCP) and 
> plotted their free energies including phonon contribution with respect to 
> the unit cell volume.

How could you get the relationship between the free energy and volume? Do 
you mean that you changed the cell volume sequentially and make a scf 
calculation to gain the free energies for the certain volume? the cell 
volume was grown bit by bit as your will, then the scf calculation did 
accordingly?

and how could you get the volume as a function of pressure as fig.2 shown? 
what kind of QE calculation could deal with it?

vega

--
From: "Eyvaz Isaev" 
Sent: Friday, August 29, 2008 9:00 PM
To: "PWSCF Forum" 
Subject: Re: [Pw_forum] something strange in rutile and anatase calculation

> Dear Vega,
>

> On the left side (under pressure) first DHCP has the lowest energy, then 
> hcp, and finally, FCC phase is the lowest in energy. So, we stated, there 
> are DHCP --> HCP and HCP --> FCC phase transitons
>
> Hope this helps.
>
> Bests,
> Eyvaz
>
> ---
> Prof. Eyvaz Isaev,
> Theoretical Physics Department, Moscow State Institute of Steel & Alloys, 
> Russia,
> Department of Physics, Chemistry, and Biology (IFM), Linkoping University, 
> Sweden
> Condensed Matter Theory Group, Uppsala University, Sweden
> Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se, eyvaz_isaev at yahoo.com
>
>
> --- On Thu, 8/28/08, vega  wrote:
>
>> From: vega 
>> Subject: Re: [Pw_forum] something strange in rutile and anatase 
>> calculation
>> To: eyvaz_isaev at yahoo.com, "PWSCF Forum" 
>> Date: Thursday, August 28, 2008, 6:05 PM
>> Dear Eyvaz,
>>
>> I have read your PNAS paper just now. I'm very
>> interesting about the phase
>> transition mentioned in your paper. But because of lack of
>> experience in
>> your scopes, I'm not very clear about the detail of the
>> calculations of
>> phase transitions.
>> In the second paragraph of Results and Discussion section,
>> you said
>> 'According to
>> our free-energy calculations, there exist two phase
>> transitions in the FeH
>> system...'. How did you simulated the two phase
>> transitions? How could you
>> calculate the Volume as a function of Pressure as shown in
>> Fig. 2? The line
>> in Fig. 2 went quite smoothly, so you may not plot it point
>> by point. How
>> could you get the line?
>>
>> thank you for reading
>>
>> vega
>>
>>
>> --
>> From: "Eyvaz Isaev" 
>> Sent: Thursday, August 28, 2008 9:25 PM
>> To: "PWSCF Forum" 
>> Subject: Re: [Pw_forum] something strange in rutile and
>> anatase calculation
>>
>> > Dear Vega,
>> >
>> > Please be not so official. I add (automatically) my
>> affiliation due to our
>> > accepted Netetiquette.
>> >
>> > Bests,
>> > Eyvaz.
>> >
>> >
>> ---
>> > Prof. Eyvaz Isaev,
>> > Theoretical Physics Department, Moscow State Institute
>> of Steel & Alloys,
>> > Russia,
>> > Department of Physics, Chemistry, and Biology (IFM),
>> Linkoping University,
>> > Sweden
>> > Condensed Matter Theory Group, Uppsala University,
>> Sweden
>> > Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se,
>> eyvaz_isaev at yahoo.com
>> >
>> >
>> > --- On Thu, 8/28/08, vega 
>> wrote:
>> >
>> >> From: vega 
>> >> Subject: Re: [Pw_forum] something strange in
>> rutile and anatase
>> >> calculation
>> >> To: eyvaz_isaev at yahoo.com, "PWSCF Forum"
>> 
>> >> Date: Thursday, August 28, 2008, 5:08 PM
>> >> Thank you for Prof. Eyvaz Isaev's hints
>> >> I'll read the excellent article as your
>> suggestion.
>> >> It's really nice of you.
>> >>
>> >> vega
>> >>
>> >> --
>> >> From: "Eyvaz Isaev"
>> 
>> >> Sent: Thursday, August 28, 2008 8:58 PM
>> >> To: "PWSCF Forum"
>> 
>> >> Subject: Re: [Pw_forum] something strange in
>> rutile and
>> >> anatase calculation
>> >>
>> >> > Hi,
>> >> >
>> >> > One more suggestion.
>> >> > As far as I know the same situation is for
>> \alpha
>> >> and \omega phases of Ti,
>> >> > as well as HCP and DHCP phases of FeH. But
>> free energy
>> >> calculations have
>> >> > shown than \alpha-Ti  and DHCP FeH are
>> stabilized
>> >> due to the phonon
>> >> > contribution.
>> >> > For FeH you can see: Eyvaz I. Isaev et al.,
>> Dynamical
>> >> stability of Fe-H in
>> >> > the Earth's mantle and core regions,
>> Proceedings
>> >> of the National Academy
>> >> > of Sciences of the USA (PNAS), 104 (22), 29
>> May 2007,
>> >> 9168. PNAS Special
>> >> > Issue "Geophysics".
>> >> >
>> >> > So, you can try follow this way, if you like.
>> >> >
>> >> > Bests,
>> >> > Eyvaz.
>> >> >
>> >> >
>> >> >
>> >>
>> ---
>> >> > Prof. Eyvaz Isaev,
>> >> > 

[Pw_forum] (no subject)

[Hande Ustunel]

Dear Anna,

The usual preliminary work that you should do before going into production
runs is to try to reproduce some experimental/previously published
theoretical results using the pseudopotentials you are interested in and
trying to see which one does better. The data you could reproduce includes
(but is definitely not limited to) bulk moduli, lattice constants, band
structures, phonon mode frequencies, properties of compounds etc. For bare
Ti, you might be hard-pressed to find data so perhaps something like TiO or
TiO2 properties would make your life easier.

Best,
Hande


-- 
Hande Toffoli
Department of Physics
Office 439
Middle East Technical University
Ankara 06531, Turkey
Tel : +90 312 210 3264
http://www.physics.metu.edu.tr/~hande

[Pw_forum] question about complex band code

[Manoj Srivastava]

Dear Alexander and PWSCF users, 
 I have a question about the subroutine PWCOND of PWSCF, which calculates
complex bands. We are solving the generalized eigen value problem, A
X=exp(ikd) B X, where A and B and are required matrices. After the
problem is solved the information about k, which is complex eigen value is
stored in band.re , band.im and band.co files, and as the name suggests
they are purely real, purely imaginary and complex eigenvalues,
respectively. Generally, for each fixed energy we get few k's either real
or imaginary or both. 
 My question is about calculation of this complex eigen value. Total no.
of k we get from solving above GEP should be equal to the number of basis
used to describe A or B. I believe the information of k is contained in
kval(:) array defined in the compbs_2 subroutine of PWCOND. When I print
it out, I do get total number of k's which are same as the total number of
basis vectors.  This is not the case with bands.re, bands.im or bands.co
files. For each energy value they have arbitrary number of k's, why is it
so? What makes it throw some k values that it gets from 'kval'? I think, I
am missing something when the code goes from 'kval(:)' to bands.re,
bands.im and bands.co files. Does someone have any idea how does the code
go from kval(:) to write bands.re, bands.im or bands.co files? 

Regards, 
Manoj Srivastava,
Physics Graduate Student, 
University of Florida,
Gainesville, FL 32601 
USA

[Pw_forum] (no subject)

[Paolo Giannozzi]

anna.ferrari at unito.it wrote:

> so this combination is accetable?
> 
>   O  15.9994   O.pw91-van_ak.UPF
>   CU 63.54 Cu.pw91-n-van_ak.UPF
>   TI 47.90 Ti.pw91-nsp-van.UPF
> 
> 

pseudopotentials of different kinds - but not of different
functionals - can be mixed, so in this respect any "combination"
is acceptable. Whether it will fit your needs, it depends (in
particular, it depends upon what your needs are!). In principle
this choice should be fine,  within the accuracy of the chosen
exchange-correlation functional, but in practise you should
always perform a few checks on simple systems for which
independent data is available

Paolo
-- 
Paolo Giannozzi, Democritos and University of Udine, Italy

[Pw_forum] (no subject)

[Hande Ustunel]

Dear Anna,

Different occupations signify that the reference configurations with
respect to which the pseudopotentials were generated were taken
differently. If you would like to know more about what this means I suggest
you read the documentation that comes with the generation code. 

The other difference is that the one that's called nsp has nonlinear core
corrections while the other one doesn't.

Best,
Hande

-- 
Hande Toffoli
Department of Physics
Office 439
Middle East Technical University
Ankara 06531, Turkey
Tel : +90 312 210 3264
http://www.physics.metu.edu.tr/~hande

[Pw_forum] something strange in rutile and anatase calculation

[Eyvaz Isaev]

Dear Wei,

Thanks a lot for bringing the paper to our attention.

I have read the paper and have 2 comments.
 
1. They used only norm-conserving pseudopotentials constructed by means of 
different methods.

2. They used only LDA, but not GGA. As it is well known (hopefully I am not 
wrong here) LDA fails for the ground state of Fe. In contrast to this, GGA does 
a good job for Fe.

So, it will be very good if Vega can calculate the total energies for the 
rutile and anatase phases in odrer to study whether their energy position is 
dependent on the choice of exchange-correlation functional. 

It might also be that there is a transferability problem for these PsPs (I can 
not prove this, just suggestion).

It is my pleasure that they also mentioned that including of phonon 
contribution might be important. 

Bests,
Eyvaz.

---
Prof. Eyvaz Isaev, 
Theoretical Physics Department, Moscow State Institute of Steel & Alloys, 
Russia, 
Department of Physics, Chemistry, and Biology (IFM), Linkoping University, 
Sweden 
Condensed Matter Theory Group, Uppsala University, Sweden 
Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se, eyvaz_isaev at yahoo.com


--- On Fri, 8/29/08, willy kohn  wrote:

> From: willy kohn 
> Subject: Re: [Pw_forum] something strange in rutile and anatase calculation
> To: "PWSCF Forum" 
> Date: Friday, August 29, 2008, 10:02 PM
> Hi, Vega:
> 
> A recent result (Jpn. J. Appl. Phys. 39 (2000) L847) showed
> that different
> pseudopotential leaded to different conclusions.
> 
> Best,
> 
> Wei
> 
> On Thu, Aug 28, 2008 at 4:28 AM, vega
>  wrote:
> 
> >  Dear all,
> >
> > It is known that the rutile is more stable than
> anatase in thermodynamics.
> > Surprisingly, when I did the vc-relax calculation by
> QE, I found
> > the calculated energy of anatase lower than rutile.
> Both vc-relax
> > calculation for rutile and anatase onverged in 6 scf
> cycles and 3 bfgs
> > steps, giving the final enthalpy = -362.7585836890 Ry
> for rutile and
> > -725.5447425835 Ry for antase. So the average energy
> of [TiO2] unit
> > is -181.3792918445 Ry for rutile and -181.386185645875
> Ry for anatase. It
> > looks like anatase is more stable than rutile. Do you
> think it was quite
> > strange?
> >
> > To make the calculation both for anatase and rutile
> comparable, I used the
> > same ecutwfc=40 Ry and ecutwfc=400 Ry, and a quite
> dense k-point mesh for
> > both case, 4x4x7 for rutile and 5x5x2 for anatase.
> >
> > for better understanding in my calculation, please
> read the input file
> > below,
> > for anatase case,
> > 
> >title = 'Anatase
> lattice' ,
> >  calculation = 'vc-relax' ,
> > restart_mode = 'from_scratch'
> ,
> >   outdir =
> >
> '/home/hjfeng/vega/TiO2/Anatase/lattice/vctest/tmp/'
> ,
> >   wfcdir = '/tmp/' ,
> >   pseudo_dir =
> '/home/hjfeng/vega/espresso-4.0/pseudo/' ,
> >   prefix = 'Anatase
> lattice' ,
> >  disk_io = 'none' ,
> >nstep = 1000 ,
> >  /
> >  
> >ibrav = 6,
> >celldm(1) = 7.1356,
> >celldm(3) = 2.5122,
> >  nat = 12,
> > ntyp = 2,
> >  ecutwfc = 40 ,
> >  ecutrho = 400 ,
> >  /
> >  
> >
> >  /
> >  
> > ion_dynamics = 'bfgs' ,
> >  /
> >  
> >cell_dynamics = 'bfgs' ,
> >  /
> > ATOMIC_SPECIES
> >Ti   47.86700  Ti.pw91-sp-van_ak.UPF
> > O   15.99940  O.pw91-van_ak.UPF
> > ATOMIC_POSITIONS crystal
> >Ti  0.00.00.0
> >Ti  0.50.50.5
> >Ti  0.00.50.25000
> >Ti  0.50.00.75000
> > O  0.00.50.04200
> > O  0.00.00.20800
> > O  0.50.50.29200
> > O  0.00.50.45800
> > O  0.50.00.54200
> > O  0.50.50.70800
> > O  0.00.00.79200
> > O  0.51.00.95800
> > K_POINTS automatic
> >   5 5 2   1 1 1
> >
> > for rutile case,
> >
> > 
> >title = Rutile_lattice ,
> >  calculation = 'vc-relax' ,
> > restart_mode = 'from_scratch'
> ,
> >   outdir =
> > '/home/vega32/TiO2/rutile/lattice/vcrelax/tmp'
> ,
> >   wfcdir = '/tmp/' ,
> >   pseudo_dir =
> '/home/vega32/espresso-4.0.1/pseudo/' ,
> >   prefix = 'Anatase
> lattice' ,
> >  disk_io = 'none' ,
> >nstep = 1000 ,
> >  /

[Pw_forum] (pseudo)

[anna.ferr...@unito.it]

>
>
> -- Messaggio originale ---
> Oggetto: Re: [Pw_forum] (no subject)
> Da:  "Eyvaz Isaev" 
> Data:Ven, 29 Agosto 2008, 3:59 pm
> A:   "PWSCF Forum" 
> --
>
>>what is the difference bewteen the two pseudo
>> Ti.pw91-sp-van_ak.UPF and Ti.pw91-nsp-van_ak.UPF
>
> sp- semi-core s and p electrons are considered as valence
> ones
>
> n- in addition, non-linear core correction is included.
>
> van- Vanderbilt type ultrasoft pseudopotetial
>
> ak- thanks Axel Kohlmeyer.
>
> Bests,
> Eyvaz.
>
> ---
> Prof. Eyvaz Isaev,
> Theoretical Physics Department, Moscow State Institute of
> Steel & Alloys, Russia,
> Department of Physics, Chemistry, and Biology (IFM),
> Linkoping University, Sweden
> Condensed Matter Theory Group, Uppsala University, Sweden
> Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se,
> eyvaz_isaev at yahoo.com
>
>
> --- On Fri, 8/29/08, anna.ferrari at unito.it
>  wrote:
>
>> From: anna.ferrari at unito.it 
>> Subject: [Pw_forum] (no subject)
>> To: pw_forum at pwscf.org
>> Date: Friday, August 29, 2008, 5:28 PM
>> dear all
>> what is the difference bewteen the two pseudo
>>
>>
>> Ti.pw91-sp-van_ak.UPF
>> and
>> Ti.pw91-nsp-van_ak.UPF
>>
>> i see a different occupatrion in the header but i do not
>> know what does it imply
>>
>>
>> thanks again
>> anna
>> ___
>> Pw_forum mailing list
>> Pw_forum at pwscf.org
>> http://www.democritos.it/mailman/listinfo/pw_forum
>
>
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>
>

[Pw_forum] (no subject)

[anna.ferr...@unito.it]

so this combination is accetable?

  O  15.9994   O.pw91-van_ak.UPF
  CU 63.54 Cu.pw91-n-van_ak.UPF
  TI 47.90 Ti.pw91-nsp-van.UPF




>
>
> -- Messaggio originale ---
> Oggetto: Re: [Pw_forum] (no subject)
> Da:  "Eyvaz Isaev" 
> Data:Ven, 29 Agosto 2008, 3:59 pm
> A:   "PWSCF Forum" 
> --
>
>>what is the difference bewteen the two pseudo
>> Ti.pw91-sp-van_ak.UPF and Ti.pw91-nsp-van_ak.UPF
>
> sp- semi-core s and p electrons are considered as valence
> ones
>
> n- in addition, non-linear core correction is included.
>
> van- Vanderbilt type ultrasoft pseudopotetial
>
> ak- thanks Axel Kohlmeyer.
>
> Bests,
> Eyvaz.
>
> ---
> Prof. Eyvaz Isaev,
> Theoretical Physics Department, Moscow State Institute of
> Steel & Alloys, Russia,
> Department of Physics, Chemistry, and Biology (IFM),
> Linkoping University, Sweden
> Condensed Matter Theory Group, Uppsala University, Sweden
> Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se,
> eyvaz_isaev at yahoo.com
>
>
> --- On Fri, 8/29/08, anna.ferrari at unito.it
>  wrote:
>
>> From: anna.ferrari at unito.it 
>> Subject: [Pw_forum] (no subject)
>> To: pw_forum at pwscf.org
>> Date: Friday, August 29, 2008, 5:28 PM
>> dear all
>> what is the difference bewteen the two pseudo
>>
>>
>> Ti.pw91-sp-van_ak.UPF
>> and
>> Ti.pw91-nsp-van_ak.UPF
>>
>> i see a different occupatrion in the header but i do not
>> know what does it imply
>>
>>
>> thanks again
>> anna
>> ___
>> Pw_forum mailing list
>> Pw_forum at pwscf.org
>> http://www.democritos.it/mailman/listinfo/pw_forum
>
>
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>
>

[Pw_forum] relax

[anna.ferr...@unito.it]

you are right
i exeed the disk space on one of the nodes I used
I checked just now

sorry...
bye
anna

>
>
> -- Messaggio originale ---
> Oggetto: Re: [Pw_forum] relax
> Da:  "Paolo Giannozzi" 
> Data:Ven, 29 Agosto 2008, 3:09 pm
> A:   "PWSCF Forum" 
> --
>
>
> On Aug 29, 2008, at 13:18 , anna.ferrari at unito.it wrote:
>
>>  from davcio : error #12
>>  i/o error in davcio
>>
>> the error in the diagonalization is connected with  the
>> negative
>> charge?
>
> there is no error in the diagonalization. The error is in
> I/O and
> means that
> the code encountered an unexpected condition, in which it
> tried to read
> data from a nonexistent or empty or corrupted file, or to
> read data
> in an
> incompatible format. It may happen especially if you are
> trying to
> restart
> from a previous run.
>
>> what can i do to avoid this error?
>
> there shouldn't be any such error if you do things
> properly (and if
> the disks
> of your machine work properly)
>
> Paolo
> ---
> Paolo Giannozzi, Dept of Physics, University of 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://www.democritos.it/mailman/listinfo/pw_forum
>
>

[Pw_forum] (no subject)

[anna.ferr...@unito.it]

thank you
i think you are right i should read more...
but for the immediate i need to choose one of them and i
do not know
if they preform similarly or not. Maybe you can help me on
this point...
anna

>
>
> -- Messaggio originale ---
> Oggetto: Re: [Pw_forum] (no subject)
> Da:  "Hande Ustunel"
> 
> Data:Ven, 29 Agosto 2008, 3:38 pm
> A:   "PWSCF Forum" 
> --
>
> Dear Anna,
>
> Different occupations signify that the reference
> configurations with
> respect to which the pseudopotentials were generated were
> taken
> differently. If you would like to know more about what
> this means I suggest
> you read the documentation that comes with the generation
> code.
>
> The other difference is that the one that's called nsp has
> nonlinear core
> corrections while the other one doesn't.
>
> Best,
> Hande
>
> --
> Hande Toffoli
> Department of Physics
> Office 439
> Middle East Technical University
> Ankara 06531, Turkey
> Tel : +90 312 210 3264
> http://www.physics.metu.edu.tr/~hande
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>
>

[Pw_forum] (no subject)

[anna.ferr...@unito.it]

dear all
what is the difference bewteen the two pseudo


Ti.pw91-sp-van_ak.UPF
and
Ti.pw91-nsp-van_ak.UPF

i see a different occupatrion in the header but i do not
know what does it imply


thanks again
anna

[Pw_forum] relax

[anna.ferr...@unito.it]

the starting geometry has been alredy optimized with
another code
at the third step i got an increased energy and afterwards
the run crashed..

can i simply change diagonalization='cg'  and restart the
calculation?


>
>
> -- Messaggio originale ---
> Oggetto: Re: [Pw_forum] relax
> Da:  "Eyvaz Isaev" 
> Data:Ven, 29 Agosto 2008, 2:52 pm
> A:   "PWSCF Forum" 
> --
>
> Dear Anna,
>
> --- On Fri, 8/29/08, anna.ferrari at unito.it
>  wrote:
>
>>
>> %%
>>  from davcio : error #12
>>  i/o error in davcio
>>
>> %%
>>
>> the error in the diagonalization is connected with  the
>> negative charge?
>
> This one is really very Frequently Asked Question. Please
> have look at the UserGude (Troubleshooting section).
>
> I do not think it is connected to small negative charge,
> rather it might be connected to the structure you study.
> If you are absolutely sure your structure is correct then
> add diagonalization='cg' line into your script.
>
>> what can i do to avoid this error?
>
> see before.
>
>> thanks again
>
> Thanks providing your affiliation.
>
>> anna
>>
>>
>
> ---
> Prof. Eyvaz Isaev,
> Theoretical Physics Department, Moscow State Institute of
> Steel & Alloys, Russia,
> Department of Physics, Chemistry, and Biology (IFM),
> Linkoping University, Sweden
> Condensed Matter Theory Group, Uppsala University, Sweden
> Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se,
> eyvaz_isaev at yahoo.com
>
>> ___
>> Pw_forum mailing list
>> Pw_forum at pwscf.org
>> http://www.democritos.it/mailman/listinfo/pw_forum
>
>
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>
>

[Pw_forum] relax

[Paolo Giannozzi]

On Aug 29, 2008, at 13:18 , anna.ferrari at unito.it wrote:

>  from davcio : error #12
>  i/o error in davcio
>
> the error in the diagonalization is connected with  the negative  
> charge?

there is no error in the diagonalization. The error is in I/O and  
means that
the code encountered an unexpected condition, in which it tried to read
data from a nonexistent or empty or corrupted file, or to read data  
in an
incompatible format. It may happen especially if you are trying to  
restart
from a previous run.

> what can i do to avoid this error?

there shouldn't be any such error if you do things properly (and if  
the disks
of your machine work properly)

Paolo
---
Paolo Giannozzi, Dept of Physics, University of Udine
via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222

[Pw_forum] something strange in rutile and anatase calculation

[willy kohn]

Hi, Vega:

A recent result (Jpn. J. Appl. Phys. 39 (2000) L847) showed that different
pseudopotential leaded to different conclusions.

Best,

Wei

On Thu, Aug 28, 2008 at 4:28 AM, vega  wrote:

>  Dear all,
>
> It is known that the rutile is more stable than anatase in thermodynamics.
> Surprisingly, when I did the vc-relax calculation by QE, I found
> the calculated energy of anatase lower than rutile. Both vc-relax
> calculation for rutile and anatase onverged in 6 scf cycles and 3 bfgs
> steps, giving the final enthalpy = -362.7585836890 Ry for rutile and
> -725.5447425835 Ry for antase. So the average energy of [TiO2] unit
> is -181.3792918445 Ry for rutile and -181.386185645875 Ry for anatase. It
> looks like anatase is more stable than rutile. Do you think it was quite
> strange?
>
> To make the calculation both for anatase and rutile comparable, I used the
> same ecutwfc=40 Ry and ecutwfc=400 Ry, and a quite dense k-point mesh for
> both case, 4x4x7 for rutile and 5x5x2 for anatase.
>
> for better understanding in my calculation, please read the input file
> below,
> for anatase case,
> 
>title = 'Anatase lattice' ,
>  calculation = 'vc-relax' ,
> restart_mode = 'from_scratch' ,
>   outdir =
> '/home/hjfeng/vega/TiO2/Anatase/lattice/vctest/tmp/' ,
>   wfcdir = '/tmp/' ,
>   pseudo_dir = '/home/hjfeng/vega/espresso-4.0/pseudo/' ,
>   prefix = 'Anatase lattice' ,
>  disk_io = 'none' ,
>nstep = 1000 ,
>  /
>  
>ibrav = 6,
>celldm(1) = 7.1356,
>celldm(3) = 2.5122,
>  nat = 12,
> ntyp = 2,
>  ecutwfc = 40 ,
>  ecutrho = 400 ,
>  /
>  
>
>  /
>  
> ion_dynamics = 'bfgs' ,
>  /
>  
>cell_dynamics = 'bfgs' ,
>  /
> ATOMIC_SPECIES
>Ti   47.86700  Ti.pw91-sp-van_ak.UPF
> O   15.99940  O.pw91-van_ak.UPF
> ATOMIC_POSITIONS crystal
>Ti  0.00.00.0
>Ti  0.50.50.5
>Ti  0.00.50.25000
>Ti  0.50.00.75000
> O  0.00.50.04200
> O  0.00.00.20800
> O  0.50.50.29200
> O  0.00.50.45800
> O  0.50.00.54200
> O  0.50.50.70800
> O  0.00.00.79200
> O  0.51.00.95800
> K_POINTS automatic
>   5 5 2   1 1 1
>
> for rutile case,
>
> 
>title = Rutile_lattice ,
>  calculation = 'vc-relax' ,
> restart_mode = 'from_scratch' ,
>   outdir =
> '/home/vega32/TiO2/rutile/lattice/vcrelax/tmp' ,
>   wfcdir = '/tmp/' ,
>   pseudo_dir = '/home/vega32/espresso-4.0.1/pseudo/' ,
>   prefix = 'Anatase lattice' ,
>  disk_io = 'none' ,
>nstep = 1000 ,
>  /
>  
>ibrav = 6,
>celldm(1) = 8.6814,
>celldm(3) = 0.6441,
>  nat = 6,
> ntyp = 2,
>  ecutwfc = 40 ,
>  ecutrho = 400 ,
>  /
>  
>
>  /
>  
> ion_dynamics = 'bfgs' ,
>  /
>  
>cell_dynamics = 'bfgs' ,
>  /
> ATOMIC_SPECIES
> O   15.99940  O.pw91-van_ak.UPF
>Ti   47.9  Ti.pw91-sp-van_ak.UPF
> ATOMIC_POSITIONS crystal
> O  0.304800.304800.0
> O  0.695200.695200.0
> O  0.195200.804800.5
> O  0.804800.195200.5
>Ti  0.50.50.5
>Ti  0.00.00.0
> K_POINTS automatic
>   4 4 7   1 1 1
>
> vega
>
> ==
> Vega Lew ( weijia liu)
> PH.D Candidate in Chemical Engineering
> State Key Laboratory of Materials-oriented Chemical Engineering
> College of Chemistry and Chemical Engineering
> Nanjing University of Technology, 210009, Nanjing, Jiangsu, China
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>
>
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[Pw_forum] (no subject)

[anna.ferr...@unito.it]

ok
i understand

i wonder if I select a restart mode  and i change
something in the input (threshold or something else)
these new information are read from the input file or
everything is read from teh scratch files of the previous
run?

thanks again
anna

>
>
> -- Messaggio originale ---
> Oggetto: Re: [Pw_forum] (no subject)
> Da:  "Paolo Giannozzi" 
> Data:Gio, 28 Agosto 2008, 3:06 pm
> A:   "PWSCF Forum" 
> --
>
>
> On Aug 27, 2008, at 17:06 , Anna Maria Ferrari wrote:
>
>> I started a relax calculation that crashed
>> now I hopefully found the error
>>
>> my question is
>> how can i restart the calculation without repeating the
>> scf?
>
>
> it depends a lot on what you did and how, whether you have
> final
> or intermediate data, and how lucky you are. The simplest
> thing to
> do is to get the last (or the best) available atomic
> positions and start
> from there
>
> P.
> ---
> Paolo Giannozzi, Dept of Physics, University of 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://www.democritos.it/mailman/listinfo/pw_forum
>
>

[Pw_forum] relax

[anna.ferr...@unito.it]

hi all!!!

i'm doing a relax cac?lculation
the program stops in this way:




 first order charge density extrapolation
 Check: negative starting charge=   -0.017665

 negative rho (up, down):  0.375E-01 0.000E+00
 first order wave-functions extrapolation
 IOS = 28

 %%
 from davcio : error #12
 i/o error in davcio
 %%

the error in the diagonalization is connected with  the
negative charge?
what can i do to avoid this error?

thanks again

anna

[Pw_forum] U calculation.

[wangqiang]

hi, everyone. i read about the U calculation in Vlab's lecture. but i am not so 
clear. could anyone discrib it in more detail?
  Lee 
  chungnam univerisity.
_
???
http://cnweb.search.live.com/video/results.aspx?q=%E5%8F%AF%E7%88%B1%E7%8C%AB%E5%92%AA=MEVHAA
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[Pw_forum] output of fildrho

[Paolo Giannozzi]

Munima Bora Sahariah wrote:

> Could anyone please help me out in reading the output fildrho files?

have a look at the header of PH/punch_plot_e.f90 and PH/punch_plot_e.f90
The output files should be readable by pp.x, in the second step (see
the description of the input, INPUT_PP.*)

Paolo
-- 
Paolo Giannozzi, Democritos and University of Udine, Italy

[Pw_forum] U calculation.

[Nicola Marzari]

wangqiang wrote:
> hi, everyone. i read about the U calculation in Vlab's lecture. but i am 
> not so clear. could anyone discrib it in more detail?
>   Lee
>   chungnam univerisity.


have a look at Matteo Cococcioni thesis, from
http://www.sissa.it/cm/phd.php   .

nicola

-- 
-
Prof Nicola Marzari   Department of Materials Science and Engineering
13-5066   MIT   77 Massachusetts Avenue   Cambridge MA 02139-4307 USA
tel 617.4522758 fax 2586534 marzari at mit.edu http://quasiamore.mit.edu

[Pw_forum] something strange in rutile and anatase calculation

[Eyvaz Isaev]

Dear Vega,

--- On Fri, 8/29/08, vega  wrote:

> How could you get the relationship between the free 
> energy and volume? Do you mean that you changed the
> cell volume sequentially and make a scf 
> calculation to gain the free energies for the certain
> volume? the cell volume was grown bit by bit as 
> your will, then the scf calculation did accordingly?
> 

We calculated total energy and phonons (then free energy) for a given set of 
volumes.

> and how could you get the volume as a function of > pressure as fig.2 shown? 
> what kind of QE calculation could deal with it?
> 
If you set up tstress=.true. you can find what is a stress (and pressure) in 
your system. Again, for a given set of the unit cell volumes. Sometime only a 
SCF calculation is enough, but sometime, especially for non-cubic systems, you 
can fix pressure and relax your system. 

Bests,
Eyvaz.

> vega
> 
> --
> From: "Eyvaz Isaev" 
> Sent: Friday, August 29, 2008 9:00 PM
> To: "PWSCF Forum" 
> Subject: Re: [Pw_forum] something strange in rutile and
> anatase calculation
> 
> > Dear Vega,
> >
> 
> > On the left side (under pressure) first DHCP has the
> lowest energy, then 
> > hcp, and finally, FCC phase is the lowest in energy.
> So, we stated, there 
> > are DHCP --> HCP and HCP --> FCC phase
> transitons
> >
> > Hope this helps.
> >
> > Bests,
> > Eyvaz
> >
> >
> ---
> > Prof. Eyvaz Isaev,
> > Theoretical Physics Department, Moscow State Institute
> of Steel & Alloys, 
> > Russia,
> > Department of Physics, Chemistry, and Biology (IFM),
> Linkoping University, 
> > Sweden
> > Condensed Matter Theory Group, Uppsala University,
> Sweden
> > Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se,
> eyvaz_isaev at yahoo.com
> >
> >
> > --- On Thu, 8/28/08, vega 
> wrote:
> >
> >> From: vega 
> >> Subject: Re: [Pw_forum] something strange in
> rutile and anatase 
> >> calculation
> >> To: eyvaz_isaev at yahoo.com, "PWSCF Forum"
> 
> >> Date: Thursday, August 28, 2008, 6:05 PM
> >> Dear Eyvaz,
> >>
> >> I have read your PNAS paper just now. I'm very
> >> interesting about the phase
> >> transition mentioned in your paper. But because of
> lack of
> >> experience in
> >> your scopes, I'm not very clear about the
> detail of the
> >> calculations of
> >> phase transitions.
> >> In the second paragraph of Results and Discussion
> section,
> >> you said
> >> 'According to
> >> our free-energy calculations, there exist two
> phase
> >> transitions in the FeH
> >> system...'. How did you simulated the two
> phase
> >> transitions? How could you
> >> calculate the Volume as a function of Pressure as
> shown in
> >> Fig. 2? The line
> >> in Fig. 2 went quite smoothly, so you may not plot
> it point
> >> by point. How
> >> could you get the line?
> >>
> >> thank you for reading
> >>
> >> vega
> >>
> >>
> >> --
> >> From: "Eyvaz Isaev"
> 
> >> Sent: Thursday, August 28, 2008 9:25 PM
> >> To: "PWSCF Forum"
> 
> >> Subject: Re: [Pw_forum] something strange in
> rutile and
> >> anatase calculation
> >>
> >> > Dear Vega,
> >> >
> >> > Please be not so official. I add
> (automatically) my
> >> affiliation due to our
> >> > accepted Netetiquette.
> >> >
> >> > Bests,
> >> > Eyvaz.
> >> >
> >> >
> >>
> ---
> >> > Prof. Eyvaz Isaev,
> >> > Theoretical Physics Department, Moscow State
> Institute
> >> of Steel & Alloys,
> >> > Russia,
> >> > Department of Physics, Chemistry, and Biology
> (IFM),
> >> Linkoping University,
> >> > Sweden
> >> > Condensed Matter Theory Group, Uppsala
> University,
> >> Sweden
> >> > Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se,
> >> eyvaz_isaev at yahoo.com
> >> >
> >> >
> >> > --- On Thu, 8/28/08, vega
> 
> >> wrote:
> >> >
> >> >> From: vega 
> >> >> Subject: Re: [Pw_forum] something strange
> in
> >> rutile and anatase
> >> >> calculation
> >> >> To: eyvaz_isaev at yahoo.com, "PWSCF
> Forum"
> >> 
> >> >> Date: Thursday, August 28, 2008, 5:08 PM
> >> >> Thank you for Prof. Eyvaz Isaev's
> hints
> >> >> I'll read the excellent article as
> your
> >> suggestion.
> >> >> It's really nice of you.
> >> >>
> >> >> vega
> >> >>
> >> >>
> --
> >> >> From: "Eyvaz Isaev"
> >> 
> >> >> Sent: Thursday, August 28, 2008 8:58 PM
> >> >> To: "PWSCF Forum"
> >> 
> >> >> Subject: Re: [Pw_forum] something strange
> in
> >> rutile and
> >> >> anatase calculation
> >> >>
> >> >> > Hi,
> >> >> >
> >> >> > One more suggestion.
> >> >> > As far as I know the same situation
> is for
> >> \alpha
> >> >> and \omega phases of Ti,
> >> >> > as well as HCP and DHCP phases of
> FeH. But
> >> free energy
> >> >> calculations have
> >> >> > shown than \alpha-Ti  and DHCP
> FeH are
> >> stabilized
> >> >> due to the phonon
> >> >> > contribution.
> >> >> > For FeH you can see: Eyvaz I. Isaev

[Pw_forum] (no subject)

[Eyvaz Isaev]

--- On Fri, 8/29/08, anna.ferrari at unito.it  wrote:

 
> so this combination is accetable?
> 
>   O  15.9994   O.pw91-van_ak.UPF
>   CU 63.54 Cu.pw91-n-van_ak.UPF
>   TI 47.90 Ti.pw91-nsp-van.UPF
>  
> 
The combination is acceptable from the point of view that you will not receive 
a message like "DFT's are incompatible". But no one can guarantee that final 
results will be OK. As Hande said you should do some simple  tests using these 
PsPs before studying of a complex system. As you have Oxygen in your system, it 
seems, it might be more complicated (like strongly correlated systems). 

Bests,
Eyvaz. 

> 
> >
> >
> > -- Messaggio originale
> ---
> > Oggetto: Re: [Pw_forum] (no subject)
> > Da:  "Eyvaz Isaev"
> 
> > Data:Ven, 29 Agosto 2008, 3:59 pm
> > A:   "PWSCF Forum"
> 
> >
> --
> >
> >>what is the difference bewteen the two pseudo
> >> Ti.pw91-sp-van_ak.UPF and Ti.pw91-nsp-van_ak.UPF
> >
> > sp- semi-core s and p electrons are considered as
> valence
> > ones
> >
> > n- in addition, non-linear core correction is
> included.
> >
> > van- Vanderbilt type ultrasoft pseudopotetial
> >
> > ak- thanks Axel Kohlmeyer.
> >
> > Bests,
> > Eyvaz.
> >
> >
> ---
> > Prof. Eyvaz Isaev,
> > Theoretical Physics Department, Moscow State Institute
> of
> > Steel & Alloys, Russia,
> > Department of Physics, Chemistry, and Biology (IFM),
> > Linkoping University, Sweden
> > Condensed Matter Theory Group, Uppsala University,
> Sweden
> > Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se,
> > eyvaz_isaev at yahoo.com
> >
> >
> > --- On Fri, 8/29/08, anna.ferrari at unito.it
> >  wrote:
> >
> >> From: anna.ferrari at unito.it
> 
> >> Subject: [Pw_forum] (no subject)
> >> To: pw_forum at pwscf.org
> >> Date: Friday, August 29, 2008, 5:28 PM
> >> dear all
> >> what is the difference bewteen the two pseudo
> >>
> >>
> >> Ti.pw91-sp-van_ak.UPF
> >> and
> >> Ti.pw91-nsp-van_ak.UPF
> >>
> >> i see a different occupatrion in the header but i
> do not
> >> know what does it imply
> >>
> >>
> >> thanks again
> >> anna
> >> ___
> >> Pw_forum mailing list
> >> Pw_forum at pwscf.org
> >> http://www.democritos.it/mailman/listinfo/pw_forum
> >
> >
> >
> > ___
> > Pw_forum mailing list
> > Pw_forum at pwscf.org
> > http://www.democritos.it/mailman/listinfo/pw_forum
> >
> >
> 
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum


  

[Pw_forum] relax

[Eyvaz Isaev]

Thanks, Stefano, actually I have mixed up the davcio error message with "pw.x 
stops with error in cdiaghg or rdiaghg".

Bests,
Eyvaz.

---
Prof. Eyvaz Isaev, 
Theoretical Physics Department, Moscow State Institute of Steel & Alloys, 
Russia, 
Department of Physics, Chemistry, and Biology (IFM), Linkoping University, 
Sweden 
Condensed Matter Theory Group, Uppsala University, Sweden 
Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se, eyvaz_isaev at yahoo.com


--- On Fri, 8/29/08, Paolo Giannozzi  wrote:

> From: Paolo Giannozzi 
> Subject: Re: [Pw_forum] relax
> To: "PWSCF Forum" 
> Date: Friday, August 29, 2008, 5:09 PM
> On Aug 29, 2008, at 13:18 , anna.ferrari at unito.it wrote:
> 
> >  from davcio : error #12
> >  i/o error in davcio
> >
> > the error in the diagonalization is connected with 
> the negative  
> > charge?
> 
> there is no error in the diagonalization. The error is in
> I/O and  
> means that
> the code encountered an unexpected condition, in which it
> tried to read
> data from a nonexistent or empty or corrupted file, or to
> read data  
> in an
> incompatible format. It may happen especially if you are
> trying to  
> restart
> from a previous run.
> 
> > what can i do to avoid this error?
> 
> there shouldn't be any such error if you do things
> properly (and if  
> the disks
> of your machine work properly)
> 
> Paolo
> ---
> Paolo Giannozzi, Dept of Physics, University of 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://www.democritos.it/mailman/listinfo/pw_forum


  

[Pw_forum] (no subject)

[Eyvaz Isaev]

>what is the difference bewteen the two pseudo
> Ti.pw91-sp-van_ak.UPF and Ti.pw91-nsp-van_ak.UPF

sp- semi-core s and p electrons are considered as valence ones

n- in addition, non-linear core correction is included.

van- Vanderbilt type ultrasoft pseudopotetial

ak- thanks Axel Kohlmeyer.

Bests,
Eyvaz.

---
Prof. Eyvaz Isaev, 
Theoretical Physics Department, Moscow State Institute of Steel & Alloys, 
Russia, 
Department of Physics, Chemistry, and Biology (IFM), Linkoping University, 
Sweden 
Condensed Matter Theory Group, Uppsala University, Sweden 
Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se, eyvaz_isaev at yahoo.com


--- On Fri, 8/29/08, anna.ferrari at unito.it  wrote:

> From: anna.ferrari at unito.it 
> Subject: [Pw_forum] (no subject)
> To: pw_forum at pwscf.org
> Date: Friday, August 29, 2008, 5:28 PM
> dear all
> what is the difference bewteen the two pseudo
> 
> 
> Ti.pw91-sp-van_ak.UPF
> and
> Ti.pw91-nsp-van_ak.UPF
> 
> i see a different occupatrion in the header but i do not
> know what does it imply
> 
> 
> thanks again
> anna
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum


  

[Pw_forum] relax

[Eyvaz Isaev]

> can i simply change diagonalization='cg'  and
> restart the calculation?

Yes, you can, of course.

bests,
Eyvaz. 


---
Prof. Eyvaz Isaev, 
Theoretical Physics Department, Moscow State Institute of Steel & Alloys, 
Russia, 
Department of Physics, Chemistry, and Biology (IFM), Linkoping University, 
Sweden 
Condensed Matter Theory Group, Uppsala University, Sweden 
Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se, eyvaz_isaev at yahoo.com


--- On Fri, 8/29/08, anna.ferrari at unito.it  wrote:

> From: anna.ferrari at unito.it 
> Subject: Re: [Pw_forum] relax
> To: eyvaz_isaev at yahoo.com, pw_forum at pwscf.org
> Date: Friday, August 29, 2008, 5:24 PM
> the starting geometry has been alredy optimized with
> another code
> at the third step i got an increased energy and afterwards
> the run crashed..
> 
> can i simply change diagonalization='cg'  and
> restart the
> calculation?
> 
> 
> >
> >
> > -- Messaggio originale
> ---
> > Oggetto: Re: [Pw_forum] relax
> > Da:  "Eyvaz Isaev"
> 
> > Data:Ven, 29 Agosto 2008, 2:52 pm
> > A:   "PWSCF Forum"
> 
> >
> --
> >
> > Dear Anna,
> >
> > --- On Fri, 8/29/08, anna.ferrari at unito.it
> >  wrote:
> >
> >>
> >>
> %%
> >>  from davcio : error #12
> >>  i/o error in davcio
> >>
> >>
> %%
> >>
> >> the error in the diagonalization is connected with
>  the
> >> negative charge?
> >
> > This one is really very Frequently Asked Question.
> Please
> > have look at the UserGude (Troubleshooting section).
> >
> > I do not think it is connected to small negative
> charge,
> > rather it might be connected to the structure you
> study.
> > If you are absolutely sure your structure is correct
> then
> > add diagonalization='cg' line into your
> script.
> >
> >> what can i do to avoid this error?
> >
> > see before.
> >
> >> thanks again
> >
> > Thanks providing your affiliation.
> >
> >> anna
> >>
> >>
> >
> >
> ---
> > Prof. Eyvaz Isaev,
> > Theoretical Physics Department, Moscow State Institute
> of
> > Steel & Alloys, Russia,
> > Department of Physics, Chemistry, and Biology (IFM),
> > Linkoping University, Sweden
> > Condensed Matter Theory Group, Uppsala University,
> Sweden
> > Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se,
> > eyvaz_isaev at yahoo.com
> >
> >> ___
> >> Pw_forum mailing list
> >> Pw_forum at pwscf.org
> >> http://www.democritos.it/mailman/listinfo/pw_forum
> >
> >
> >
> > ___
> > Pw_forum mailing list
> > Pw_forum at pwscf.org
> > http://www.democritos.it/mailman/listinfo/pw_forum
> >
> >
> 
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum


  

[Pw_forum] something strange in rutile and anatase calculation

[Eyvaz Isaev]

Dear Vega,

As you can see we considered three FeH phases (FCC, HCP, and DHCP) and plotted 
their free energies including phonon contribution with respect to the unit cell 
volume.
On the left side (under pressure) first DHCP has the lowest energy, then hcp, 
and finally, FCC phase is the lowest in energy. So, we stated, there are DHCP 
--> HCP and HCP --> FCC phase transitons

Hope this helps.

Bests,
Eyvaz

---
Prof. Eyvaz Isaev, 
Theoretical Physics Department, Moscow State Institute of Steel & Alloys, 
Russia, 
Department of Physics, Chemistry, and Biology (IFM), Linkoping University, 
Sweden 
Condensed Matter Theory Group, Uppsala University, Sweden 
Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se, eyvaz_isaev at yahoo.com


--- On Thu, 8/28/08, vega  wrote:

> From: vega 
> Subject: Re: [Pw_forum] something strange in rutile and anatase calculation
> To: eyvaz_isaev at yahoo.com, "PWSCF Forum" 
> Date: Thursday, August 28, 2008, 6:05 PM
> Dear Eyvaz,
> 
> I have read your PNAS paper just now. I'm very
> interesting about the phase 
> transition mentioned in your paper. But because of lack of
> experience in 
> your scopes, I'm not very clear about the detail of the
> calculations of 
> phase transitions.
> In the second paragraph of Results and Discussion section,
> you said 
> 'According to
> our free-energy calculations, there exist two phase
> transitions in the FeH 
> system...'. How did you simulated the two phase
> transitions? How could you 
> calculate the Volume as a function of Pressure as shown in
> Fig. 2? The line 
> in Fig. 2 went quite smoothly, so you may not plot it point
> by point. How 
> could you get the line?
> 
> thank you for reading
> 
> vega
> 
> 
> --
> From: "Eyvaz Isaev" 
> Sent: Thursday, August 28, 2008 9:25 PM
> To: "PWSCF Forum" 
> Subject: Re: [Pw_forum] something strange in rutile and
> anatase calculation
> 
> > Dear Vega,
> >
> > Please be not so official. I add (automatically) my
> affiliation due to our 
> > accepted Netetiquette.
> >
> > Bests,
> > Eyvaz.
> >
> >
> ---
> > Prof. Eyvaz Isaev,
> > Theoretical Physics Department, Moscow State Institute
> of Steel & Alloys, 
> > Russia,
> > Department of Physics, Chemistry, and Biology (IFM),
> Linkoping University, 
> > Sweden
> > Condensed Matter Theory Group, Uppsala University,
> Sweden
> > Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se,
> eyvaz_isaev at yahoo.com
> >
> >
> > --- On Thu, 8/28/08, vega 
> wrote:
> >
> >> From: vega 
> >> Subject: Re: [Pw_forum] something strange in
> rutile and anatase 
> >> calculation
> >> To: eyvaz_isaev at yahoo.com, "PWSCF Forum"
> 
> >> Date: Thursday, August 28, 2008, 5:08 PM
> >> Thank you for Prof. Eyvaz Isaev's hints
> >> I'll read the excellent article as your
> suggestion.
> >> It's really nice of you.
> >>
> >> vega
> >>
> >> --
> >> From: "Eyvaz Isaev"
> 
> >> Sent: Thursday, August 28, 2008 8:58 PM
> >> To: "PWSCF Forum"
> 
> >> Subject: Re: [Pw_forum] something strange in
> rutile and
> >> anatase calculation
> >>
> >> > Hi,
> >> >
> >> > One more suggestion.
> >> > As far as I know the same situation is for
> \alpha
> >> and \omega phases of Ti,
> >> > as well as HCP and DHCP phases of FeH. But
> free energy
> >> calculations have
> >> > shown than \alpha-Ti  and DHCP FeH are
> stabilized
> >> due to the phonon
> >> > contribution.
> >> > For FeH you can see: Eyvaz I. Isaev et al.,
> Dynamical
> >> stability of Fe-H in
> >> > the Earth's mantle and core regions,
> Proceedings
> >> of the National Academy
> >> > of Sciences of the USA (PNAS), 104 (22), 29
> May 2007,
> >> 9168. PNAS Special
> >> > Issue "Geophysics".
> >> >
> >> > So, you can try follow this way, if you like.
> >> >
> >> > Bests,
> >> > Eyvaz.
> >> >
> >> >
> >> >
> >>
> ---
> >> > Prof. Eyvaz Isaev,
> >> > Theoretical Physics Department, Moscow State
> Institute
> >> of Steel & Alloys,
> >> > Russia,
> >> > Department of Physics, Chemistry, and Biology
> (IFM),
> >> Linkoping University,
> >> > Sweden
> >> > Condensed Matter Theory Group, Uppsala
> University,
> >> Sweden
> >> > Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se,
> >> eyvaz_isaev at yahoo.com
> >> >
> >> >
> >> > --- On Thu, 8/28/08, Nicola Marzari
> >>  wrote:
> >> >
> >> >> From: Nicola Marzari
> 
> >> >> Subject: Re: [Pw_forum] something strange
> in
> >> rutile and anatase
> >> >> calculation
> >> >> To: "PWSCF Forum"
> >> 
> >> >> Date: Thursday, August 28, 2008, 3:01 PM
> >> >> vega wrote:
> >> >> > Dear all,
> >> >> >
> >> >> > It is known that the rutile is more
> stable
> >> than
> >> >> anatase in
> >> >> > thermodynamics. Surprisingly, when I
> did the
> >> vc-relax
> >> >> calculation by
> >> >> > QE, I found the calculated energy of
> 

[Pw_forum] relax

[Eyvaz Isaev]

Dear Anna,

--- On Fri, 8/29/08, anna.ferrari at unito.it  wrote:

> 
> %%
>  from davcio : error #12
>  i/o error in davcio
> 
> %%
> 
> the error in the diagonalization is connected with  the
> negative charge?

This one is really very Frequently Asked Question. Please have look at the 
UserGude (Troubleshooting section).

I do not think it is connected to small negative charge, rather it might be 
connected to the structure you study.
If you are absolutely sure your structure is correct then add 
diagonalization='cg' line into your script.

> what can i do to avoid this error?

see before. 

> thanks again
 
Thanks providing your affiliation.

> anna
> 
> 

---
Prof. Eyvaz Isaev, 
Theoretical Physics Department, Moscow State Institute of Steel & Alloys, 
Russia, 
Department of Physics, Chemistry, and Biology (IFM), Linkoping University, 
Sweden 
Condensed Matter Theory Group, Uppsala University, Sweden 
Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se, eyvaz_isaev at yahoo.com

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