Prof. Giannozzi: Thank you very much for your kindly reply. I think this is my problem to understand Fvib. I have also checked Axel van de Walle's Ph.D thesis, and found that free energy should be Fvib+Fconf-TSvib-TSconf. In 0GPa pressure case, Fconf should equal to total energy. Therefore I cannot obtain the right Free Energy vs Volume curve as a result of using Fvib alone.
-- GAO Zhe CMC Lab, MSE, SNU, Seoul, S.Korea At 2011-08-30 03:42:31,"Paolo Giannozzi" <giannozz at democritos.it> wrote: > >On Aug 22, 2011, at 4:36 , GAO Zhe wrote: > >> However, the free energy kept decreasing as a monotone decreasing >> function of lattice parameter > >you mean: the "vibrational free energy" alone, or "the sum of the >energy and of the vibrational free energy"? the vibrational free >energy should be a small correction to the total energy. > >P. >--- >Paolo Giannozzi, Dept of Chemistry&Physics&Environment, >Univ. 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 -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110831/0419a2d7/attachment.htm