Yea dear Linh, I have used the converged cell parameter from vc-relax calculation for scf run,
Thnaks, mohnish On Sun, Apr 18, 2010 at 8:33 PM, Ngoc Linh Nguyen <nnlinh at sissa.it> wrote: > > > Dear Hanyu ! > > Thanks for your reply. As you now the default value > > for > > the pressure in PWSCF is 0.5. > > This value should be 0.0 as the default value (see in input PW website) > > > I am using that value as convergence > > threshold > > but when I am doing scf calculation with the geometrical parameters value > > obtained from the vc-relax calculation the pressure value is different > > from > > vc-relax final run. And as you know pressure will effect the phonon > > dispresion relation..Can you please give me any suggestion, > > Before doing scf calculations, have you changed the cell-parameters in scf > input file as same as the converged cell-parameters from vc-relax? > > Best regards, > > Linh > > > > > > > Thanks alot, > > MOHNISH > > > > On Sun, Apr 18, 2010 at 3:00 PM, Hanyu <ouuing at gmail.com> wrote: > > > >> dear mohnish : > >> I think you should check it carefully again. I don't think it should > >> be happen. In fact, the stress of scf and vc-relax should be the same. > >> but if the stress is not the hydrostatic pressure, the result is not > >> be believed. you have to relax the structure until the stress of the > >> phase is what you want. > >> > >> best regards. > >> > >> Hanyu > >> > >> On Sun, Apr 18, 2010 at 11:16 AM, mohnish pandey > >> <mohnish.iitk at gmail.com> > >> wrote: > >> > Dear users, > >> > I want to do phonon calculation for some structures, > >> but > >> > after geometry optimization when I am using optimized geometry > >> parameters > >> > for scf calculation there is difference in stress of scf calculation > >> and > >> > vc-relax calculation which is changing phonon dispersion. Can anybody > >> please > >> > tell me if there is any option to use the data of relax or vc-relax > >> > calculation for phonon dispersion.. Or can I doing phonon calculation > >> along > >> > with relax or vc-relax calculation.? > >> > Thanks a lot in advance, > >> > > >> > -- > >> > Regards, > >> > MOHNISH, > >> > ----------------------------------------------------------------- > >> > Mohnish Pandey > >> > Y6927262,4th Year dual degree student, > >> > Department of Chemical Engineering, > >> > IIT KANPUR > >> > 09235721300 > >> > ----------------------------------------------------------------- > >> > > >> > _______________________________________________ > >> > Pw_forum mailing list > >> > Pw_forum at pwscf.org > >> > http://www.democritos.it/mailman/listinfo/pw_forum > >> > > >> > > >> > >> > >> > >> -- > >> -=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=**=-=**=-=**=-=*=-=*=-=*=-=*=-=*=- > >> Hanyu Liu(?????????), > >> MS. > >> State key Laboratory of Superhard Materials, Jilin University, China > >> Email: liuhanyu08 at mails.jlu.edu.cn ouuing at gmail.com > >> _______________________________________________ > >> Pw_forum mailing list > >> Pw_forum at pwscf.org > >> http://www.democritos.it/mailman/listinfo/pw_forum > >> > > > > > > > > -- > > Regards, > > MOHNISH, > > ----------------------------------------------------------------- > > Mohnish Pandey > > Y6927262,4th Year dual degree student, > > Department of Chemical Engineering, > > IIT KANPUR > > 09235721300 > > ----------------------------------------------------------------- > > _______________________________________________ > > Pw_forum mailing list > > Pw_forum at pwscf.org > > http://www.democritos.it/mailman/listinfo/pw_forum > > > > > ----------------------------------------------------- > Nguyen Ngoc Linh, PhD Student > c/o: SISSA & CNR-INFM Democritos, > via Beirut 2-4, 34014 Trieste (Italy) > email: nnlinh at sissa.it > phone: +39 04 03787 319 > skype: ngoclinh84phys > ----------------------------------------------------- > "The physics is theoretical but the fun is real" > > > ---------------------------------------------------------------- > SISSA Webmail https://webmail.sissa.it/ > Powered by SquirrelMail http://www.squirrelmail.org/ > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > -- Regards, MOHNISH, ----------------------------------------------------------------- Mohnish Pandey Y6927262,4th Year dual degree student, Department of Chemical Engineering, IIT KANPUR 09235721300 ----------------------------------------------------------------- -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20100419/69117321/attachment.htm