if the defect concentration is too hight, when you do vc-relax the lattice parameter will be re-optimized. In reality, the defect concentration is about zero.
On Fri, Sep 18, 2009 at 8:43 AM, xirainbow <nkxirainbow at gmail.com> wrote: > Dear: > > When you calculate without vc-relax, you deal with a point defect. > When you use vc-relax, you change the crystal parameters. That is to say, > you deal with a new kind of crystal, not a point defect. > It is just my own point of view ?? > > > >> >> Ali Kazempour >> Physics department, Isfahan University of Technology >> 84156 Isfahan, Iran. Tel-1: +98 311 391 3733 >> Fax: +98 311 391 2376 Tel-2: +98 311 391 2375 >> >> --- On *Fri, 9/18/09, ali kazempour <kazempoor2000 at yahoo.com>* wrote: >> >> >> From: ali kazempour <kazempoor2000 at yahoo.com> >> Subject: defect formation energy >> To: forum at democritos.it >> Date: Friday, September 18, 2009, 5:31 AM >> >> >> Hi >> for study of point defect , i do relax calculation and obtain positive >> defect formation energy while by vc-relax i gain negative. ? >> what is the difference between positive and negative formation energy? >> waht is the physical reasons? >> thanks a lot >> Ali Kazempour >> Physics department, Isfahan University of Technology >> 84156 Isfahan, Iran. Tel-1: +98 311 391 3733 >> Fax: +98 311 391 2376 Tel-2: +98 311 391 2375 >> >> > > > -- > ____________________________________ > Hui Wang > School of physics, Nankai University, Tianjin, China > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > -- -------------------------------------------------- Duy Le PhD Student Department of Physics University of Central Florida. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20090918/7e6b8cca/attachment.htm
