[Pw_forum] how i can find tetragonal phase with PZT structure

[mtt physics]

.
> > >
> > > Office: 2025 Physics Research Building
> > > ==
> > >
> > > On Tue, 13 Oct 2009, Stefano Baroni wrote:
> > >
> > >
> > >> On Oct 12, 2009, at 5:34 PM, William Parker wrote:
> > >>
> > >>
> > >>> Hello everyone,
> > >>>
> > >>> Is there a publication that contains a more detailed description of
> > >>> the
> > >>> Fock exchange minimization scheme in QE than the reference paper
> > >>> appendix
> > >>> or the README in examples/EXX_example?
> > >>>
> > >> something (not much) is here: http://stacks.iop.org/0953-8984/21/395502
> > >>
> > >> have you tried it out?
> > >>
> > >> SB
> > >>
> > >> ---
> > >> 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
> > >> 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
> >
> 
> 
> --
> 
> Message: 8
> Date: Wed, 14 Oct 2009 17:16:44 -0700 (PDT)
> From: vtmtrinh at caltech.edu
> Subject: [Pw_forum] Questions on phonon calculation in Example02 and
> 06
> To: pw_forum at pwscf.org
> Message-ID:
> <4237.137.78.73.28.1255565804.squirrel at webmail.caltech.edu>
> Content-Type: text/plain;charset=iso-8859-1
> 
> Dear PWSCF Users,
> 
> Since I would like to compare the phonon calculations by using 2
> different ways as explained in Example02 and Example06, I rerun the
> whole calculation in Example06. Everything was fine. I then rerun the
> calculation of one specific q-point (-0.25, 0.25, -0.25) from Example06,
> but using the way shown in Example02, ie. performing scf, calculation at
> Gamma, nscf at q, and phonon at q. I compared the 2 results from the 2
> methods, I saw that both ways gave the same phonon frequencies, but the
> displacement vectors are totally are different. I thought both should
> have yielded the same results. I apprciate if you could you help me to
> explain this.
> 
> Below are the results:
> 
> Following Example06:
> 
> q = ( -0.25000 0.25000 -0.25000 )
> **
> omega( 1) = 1.765425 [THz] = 58.888627 [cm-1]
> ( -0.141032 0.460061 0.040238 0.471692 0.181270 0.011631 )
> ( -0.113839 0.478895 0.071975 0.478895 0.185814 0.00 )
> omega( 2) = 1.765425 [THz] = 58.888627 [cm-1]
> ( 0.253069 0.173719 -0.286906 0.139072 -0.539975 -0.034647 )
> ( 0.269727 0.160766 -0.283781 0.160766 -0.553509 0.00 )
> omega( 3) = 4.536195 [THz] = 151.312190 [cm-1]
> ( -0.204646 -0.290110 0.204646 0.290110 -0.204646 -0.290110 )
> ( -0.455290 0.00 0.455290 0.00 -0.455290 0.00 )
> omega( 4) = 11.004563 [THz] = 367.075159 [cm-1]
> ( -0.081755 -0.466090 0.446212 -0.432214 0.527968 0.033877 )
> ( 0.039228 0.161901 -0.147017 0.161901 -0.186245 0.00 )
> omega( 5) = 11.004563 [THz] = 367.075159 [cm-1]
> ( -0.451526 0.406642 0.107022 0.442481 0.558547 0.035839 )
> ( 0.149460 -0.153037 -0.047572 -0.153037 -0.197033 0.00 )
> omega( 6) = 12.136012 [THz] = 404.816481 [cm-1]
> ( -0.320406 -0.454213 0.320406 0.454213 -0.320406 -0.454213 )
> ( 0.156090 0.00 -0.156090 0.00 0.156090 0.00 )
> **
> 
> 
> 
> Following Example02
> 
> q = ( -0.25000 0.25000 -0.25000 )
> **
> omega( 1) = 1.765442 [THz] = 58.889209 [cm-1]
> ( 0.318551 0.007983 -0.249525 -0.028467 -0.568077 -0.036450 )
> ( 0.325719 -0.012716 -0.256595 -0.012716 -0.582315 0.00 )
> omega( 2) = 1.765442 [THz] = 58.889209 [cm-1]
> ( -0.451869 0.141577 -0.493353 0.138915 -0.041485 -0.002662 )
> ( -0.452021 0.174129 -0.494545 0.174129 -0.042524 0.00 )
> omega( 3) = 4.536219 [THz] = 151.312986 [cm-1]
> ( -0.204633 -0.290122 0.204633 0.290122 -0.204633 -0.290122 )
> ( -0.455289 0.00 0.455289 0.00 -0.455289 0.00 )
> omega( 4) = 11.004565 [THz] = 367.075220 [cm-1]
> ( -0.184054 0.641087 -0.184054 0.641087 0.00 0.00 )
> ( 0.050209 -0.229371 0.050209 -0.229371 0.00 0.00 )
> omega( 5) = 11.004565 [THz] = 367.075220 [cm-1]
> ( 0.384293 0.024658 -0.384293 -0.024658 -0.768587 -0.049316 )
> ( -0.135563 0.00 0.135563 0.00 0.271126 0.00 )
> omega( 6) = 12.136049 [THz] = 404.817695 [cm-1]
> ( -0.320383 -0.454229 0.320383 0.454229 -0.320383 -0.454229 )
> ( 0.156091 0.00 -0.156091 0.00 0.156091 0.00 )
> **
> 
> 
> Best,
> 
> MyTrinh Vo
> 
> 
> 
> 
> --
> 
> ___
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> 
> End of Pw_forum Digest, Vol 28, Issue 36
> 
  
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[Pw_forum] Everything you always wanted to know about QE,

[lan haiping]

Thanks for  the efforts.


Regards,

Hai-Ping

On Thu, Oct 15, 2009 at 9:47 PM, Nicola Marzari  wrote:

>
>
> but were afraid to ask...
>
>
> Dear All,
>
>
> now all (or most of your questions) have been answered ! As you might
> recall,
> this summer NSF/ICMR and Democritos organized a summer school on materials
> modeling using QE at the University of Santa Barbara. Sadly, we had only
> 48 slots
> (half US-based, half from outside) and 300 applicants. So, we decided to
> put all
> the lectures (slides, videos !, and tutorials) on the web.
>
> You can find all of these linked from http://media.quantum-espresso.org  .
>
> A few videos are corrupted (but not the audio) and a few of the keynote
> lectures
> are missing, but overall this is a very large and articulate amount of
> material that
> can act for everyone on this mailing list as the first resource to learn
> about all the
> different features of QE. So, if you have a question on the basics, or
> on some advanced
> techniques, go first through the relevant part of this material - most
> questions are
> answered there.
>
> Many thanks to everyone that made this possible: all the lecturers,
> keynote speakers, NSF and Democritos, but especially the ICTP Science
> Dissemination Unit (Enrique Canessa, Marco Zennaro and Carlo Fonda) for
> setting up the recording system OpenEyA, Gabriele Sclauzero (SISSA and
> Democritos) and
> Paolo Umari  (Democritos) for recording the lectures, and Alberto
> Campagnari (Democritos) for
> preparing them online.
>
> Enjoy !
>
> 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 mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>



-- 
Hai-Ping Lan
Department of Electronics ,
Peking University , Bejing, 100871
lanhaiping at gmail.com, hplan at pku.edu.cn
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[Pw_forum] total force ascend in the course of VC-relax

[Q.J.Wang]

Dear all
I did geometry optimization with vc-relax in a supercell. When I increase 
the concentration of doped atoms ,the value of total force ascend instead of 
declining.Before I did not increase the concentration of doped atoms ,It 
converges well .Anyone who encounter the same problem as me ?
The second problem is when I increase the relative distance of the two 
doped atoms in the supercell and did geometry optimization with vc-relax,and 
the error turn up as like : from c_bands : error # 1
too many bands are not converged
So I am puzzled why before I increase relative position of two doped atoms the 
vc-relax converged and the latter turns up error in the same parameter .
Any advice will be appreciated .
--

Best regards
 
Q.J.Wang
 
XiangTan University 
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[Pw_forum] partial phonon density of state

[zq wu]

Dear all,

I need to calculate the partial phonon density of state. Has the Eyvaz's
code, which can calculate the partial phonon density of state, been
incorporated in quantum expresso?

Thanks

Zhongqing
-- 

CACS University of Southern California
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[Pw_forum] how to use startingpot for different ecutwfc?

[Duy Le]

Hi,First of all, I am not sure why you changed number of k-points and/or
ecutwfc, the wave function was read successfully. As I remembers, the wave
functions expansion has k and G as indexes. So, when you changed number of
k-points or cutoff energy, the wavefunction must not be read successfully.
Anyway, this is not the problem you are asking.

For "dimensions do not match": The dimensions of charge density usually
depends on the size of unit cell and the energy cutoff for charge density.
You probably changed the energy cutoff for charge density.

If you do want to change the energy cutoff for charge density, you should
consider to fix nr1, nr2, and nr3.

D.
--
Duy Le
PhD Student
Department of Physics
University of Central Florida.


On Thu, Oct 15, 2009 at 6:19 PM, Ricardo Faccio  wrote:

> Dear QE users
> I want to perform a convergence study on k-points and ecut for any
> selected material. Let?s take Si for example.
> I used ?startingwfc? and ?startingpot? in order to use the last
> convergence stuff as a starting point for the next one.
> In the case of k-points there is no problems, we can use the
> charge-density and wfc without problems. But, when we increase the Ecut,
> pw.x stops with this error:
> %%%
> from read_rho_xml : error # 1
> dimensions do not match
>  %%%
> Is there exist any way to use the previous charge-density in order to
> generate the starting potential? In particular looking for convergence in
> Ecutwfc
> I spent lot of time starting from the superposition of atoms.
> Thanks in advance.
> Ricardo
>
> --
>  -
> -   Dr. Ricardo Faccio
>
>  Mail: Cryssmat-Lab., C?tedra de F?sica, DETEMA
>  Facultad de Qu?mica, Universidad de la Rep?blica
>   Av. Gral. Flores 2124, C.C. 1157
>   C.P. 11800, Montevideo, Uruguay.
>  E-mail: rfaccio at fq.edu.uy
>  Phone: 598 2 9241860 Int. 109
> 598 2 9290705
>  Fax:598 2 9241906
>  Web:  http://cryssmat.fq.edu.uy/ricardo/ricardo.htm
>
>
>
>
> ___
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> http://www.democritos.it/mailman/listinfo/pw_forum
>
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[Pw_forum] how to use startingpot for different ecutwfc?

[Ricardo Faccio]

Dear QE users
I want to perform a convergence study on k-points and ecut for any
selected material. Let?s take Si for example.
I used ?startingwfc? and ?startingpot? in order to use the last
convergence stuff as a starting point for the next one.
In the case of k-points there is no problems, we can use the
charge-density and wfc without problems. But, when we increase the Ecut,
pw.x stops with this error:
%%%
 from read_rho_xml : error # 1
 dimensions do not match
 %%%
Is there exist any way to use the previous charge-density in order to
generate the starting potential? In particular looking for convergence in
Ecutwfc
I spent lot of time starting from the superposition of atoms.
Thanks in advance.
Ricardo

-- 
  -
-   Dr. Ricardo Faccio

  Mail: Cryssmat-Lab., C?tedra de F?sica, DETEMA
  Facultad de Qu?mica, Universidad de la Rep?blica
   Av. Gral. Flores 2124, C.C. 1157
   C.P. 11800, Montevideo, Uruguay.
  E-mail: rfaccio at fq.edu.uy
  Phone: 598 2 9241860 Int. 109
 598 2 9290705
  Fax:598 2 9241906
  Web:  http://cryssmat.fq.edu.uy/ricardo/ricardo.htm

[Pw_forum] How to calculate the isotope effect

[loc duong ding]

Dear PWSCF users,

I am trying to consider effect of isotope.?How can I?get the PP of isotope 
(ex.?O(16) and?O(17))?

Best,?---
Loc Duong Dinh
Ms-Ph.D Student
Sungkyunkwan Advanced Institute of Nanotechnology,
Sungkyunkwan University,
Suwon, 440-746, Korea 
Email: mambom1902 at yahoo.com, ddloc at skku.edu 


  

[Pw_forum] how i can find tetragonal phase with PZT structure

[Lorenzo Paulatto]

In data 15 ottobre 2009 alle ore 17:17:36, mtt physics  
 ha scritto:
> I have a problem with calculate c/a for tetragonal phase

Deat mtt,
it is actually very easy: just take c and divide it by a, that's the  
number you are looking for!

Now, seriously; if you want some helpful advice you should provide more  
information about your problem. E.g. the input/output of your calculation,  
the kind of system, the pseudopotential you are using.

Have you had a look at the example files? They used to be bundled together  
with the code, but they became too big, you can download them from here:  


Finally, the videos from a 2-week series of lectures on how to use  
quantum-espresso has recently been published on-line: you can find them  
here: .  
Please take some time watching at least the first few (by Baroni,  
Narasimhan, de Gironcoli and Dal Corso),they provide the very basic  
knowledge you really need to have before starting with electronic  
structure calculations. It is boring, I know, but it pays back in saved  
time.

best regards

-- 
Lorenzo Paulatto
SISSA  &  DEMOCRITOS (Trieste)
phone: +39 040 3787 511
skype: paulatz
www:   http://people.sissa.it/~paulatto/

 *** save italian brains ***
  http://saveitalianbrains.wordpress.com/

[Pw_forum] total force ascend in the course of VC-relax

[Lorenzo Paulatto]

In data 15 ottobre 2009 alle ore 15:38:39, Q.J.Wang  ha  
scritto:

> Dear all
> I did geometry optimization with vc-relax in a supercell. When I  
> increase the concentration of doped atoms ,the value of total force  
> ascend instead of declining.Before I did not increase the concentration  
> of doped atoms ,It converges well .Anyone who encounter the same problem  
> as me ?

I sounds normal to me, when you perturb the system you will have to redo  
the relaxation... why do you find it puzzling?


> The second problem is when I increase the relative distance of the  
> two doped atoms in the supercell and did geometry optimization with  
> vc-relax,and the error turn up as like : from c_bands : error # 1
> too many bands are not converged
> So I am puzzled why before I increase relative position of two doped  
> atoms the vc-relax converged and the latter turns up error in the same  
> parameter .

It happens with peculiar configurations, the easiest way to get rid of it  
is normally to increase the number of bands.

cheers



-- 
Lorenzo Paulatto
SISSA  &  DEMOCRITOS (Trieste)
phone: +39 040 3787 511
skype: paulatz
www:   http://people.sissa.it/~paulatto/

 *** save italian brains ***
  http://saveitalianbrains.wordpress.com/

[Pw_forum] Everything you always wanted to know about QE,

[Nicola Marzari]

but were afraid to ask...


Dear All,


now all (or most of your questions) have been answered ! As you might 
recall,
this summer NSF/ICMR and Democritos organized a summer school on materials
modeling using QE at the University of Santa Barbara. Sadly, we had only 
48 slots
(half US-based, half from outside) and 300 applicants. So, we decided to 
put all
the lectures (slides, videos !, and tutorials) on the web.

You can find all of these linked from http://media.quantum-espresso.org  .

A few videos are corrupted (but not the audio) and a few of the keynote 
lectures
are missing, but overall this is a very large and articulate amount of 
material that
can act for everyone on this mailing list as the first resource to learn 
about all the
different features of QE. So, if you have a question on the basics, or 
on some advanced
techniques, go first through the relevant part of this material - most 
questions are
answered there.

Many thanks to everyone that made this possible: all the lecturers,
keynote speakers, NSF and Democritos, but especially the ICTP Science
Dissemination Unit (Enrique Canessa, Marco Zennaro and Carlo Fonda) for
setting up the recording system OpenEyA, Gabriele Sclauzero (SISSA and 
Democritos) and
Paolo Umari  (Democritos) for recording the lectures, and Alberto 
Campagnari (Democritos) for
preparing them online.

Enjoy !

 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] Questions on phonon calculation in Example02 and 06

[Paolo Giannozzi]

On Oct 15, 2009, at 2:16 , vtmtrinh at caltech.edu wrote:

> I compared the 2 results from the 2 methods, I saw that both ways gave
> the same phonon frequencies, but the displacement vectors are totally
> different.

no they aren't. Displacement vectors for non-degenerate modes (number 3
and 6) are the same (within numerical accuracy). For degenerate  
modes, you
get different linear combinations (because of the way matrix  
diagonalization
works), but the subspace spanned by the two sets of degenerate  
eigenvectors
is the same (I haven't verified, but I am sure it is: plase verify)

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