Dear Paolo, I then test this result with ph.x code. The born effetive charge tensors obtained are greatly consistent with published results in Zhong et al (PRL.72.3618) , for O sites (-5.81,-2.57,- 2.57) , for Pb sites (3.92,3.92,3.92) (all are diagonal elements of E-U tensors).
I then recalculated with Berry Phase method, and still cannot find satisfactory results for O sites. A typical resulted tensor is (-5.84, -1.90 ,-1.98). Would you please give some comments ? regards, h.p On 1/14/07, Paolo Giannozzi <giannozz at nest.sns.it> wrote: > > > On Jan 13, 2007, at 6:58 , lan haiping wrote: > > > I have a question about berry phase calculation for born effetive > > charge implemented in espresso. [...] I could obtain born > > effective tensor of Pb site > > about 3.9 -3.92 e whenever i increase ecutoffrho , conv_thr or use > > denser > > kmesh. But the born effective tensor of O sites , i.e . the three > > diagonal > > elements are not consistent with the result of Zhong et al (PRL. > > 72.3618). > > The values i obtained are -1.98 , -5.85, -1.90e respectively for > > 3 different > > directions. > > did you try linear response? If you get the same result, that's it > P. > --- > Paolo Giannozzi, Democritos and University of Udine, Italy > > > _______________________________________________ > 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 -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/attachments/20070121/03a88def/attachment.htm
