Dear Hanyu ! Thanks for your reply. As you now the default value for the pressure in PWSCF is 0.5. 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,
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 ----------------------------------------------------------------- -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20100418/33c1d112/attachment.htm