The evidence I could find is that with LDA/PBE/PBEsol/mBJ Born charges are slightly too large compared to experiment. Hybrid methods give slightly (10%) smaller values which seem to be closer to experiment. A caveat is that I could not find extensive, good experimental data.
N.B., of course a metal does not have a Born charge... --- Prof Laurence Marks "Research is to see what everyone else has seen, and to think what nobody else has thought", Albert Szent-Gyorgi www.numis.northwestern.edu On Mon, Sep 7, 2020, 10:41 Rubel, Oleg <rub...@mcmaster.ca> wrote: > To add to the discussion, here is a tutorial "Born effective charge of > GaN" from the last WIEN2k workshop ( > https://urldefense.com/v3/__http://susi.theochem.tuwien.ac.at/events/ws2019/Exercises_19-tot.pdf__;!!Dq0X2DkFhyF93HkjWTBQKhk!GdNcHpBDzmc0bKkfTPuHupsF84fQAHYEE4SpKCD6n0q9kD52LHuFkiYuzaf5sysilMJE0g$ > ). In this case LDA performs very well. One can try to do TBmBJ to see a > difference. > > Some systems with a small Eg (for example InN) have Eg = 0 at LDA/GGA > level, which created a problem for Berry phase calculations that need a > gap. In this case TBmBJ (or DFT+U) would be your best option. > > I hope it will help > Oleg > > -- > Oleg Rubel (PhD, PEng) > Department of Materials Science and Engineering > McMaster University > JHE 359, 1280 Main Street West, Hamilton, Ontario L8S 4L8, Canada > Email: rub...@mcmaster.ca > Tel: +1-905-525-9140, ext. 24094 > Web: > https://urldefense.com/v3/__http://olegrubel.mcmaster__;!!Dq0X2DkFhyF93HkjWTBQKhk!GdNcHpBDzmc0bKkfTPuHupsF84fQAHYEE4SpKCD6n0q9kD52LHuFkiYuzaf5sys_YsgAaQ$ > > ________________________________________ > From: Wien <wien-boun...@zeus.theochem.tuwien.ac.at> on behalf of > Laurence Marks <laurence.ma...@gmail.com> > Sent: Saturday, September 5, 2020 22:39 > To: A Mailing list for WIEN2k users > Subject: Re: [Wien] Born effective charge calculation > > From what I have found and my tests, either -eece or +U are better as > GGA's overestimate. MBJ does not appear to be better. However, values are > often not that well measured experimentally. > > --- > Prof Laurence Marks > "Research is to see what everyone else has seen, and to think what nobody > else has thought", Albert Szent-Gyorgi > http://www.numis.northwestern.edu<http://www.numis.northwestern.edu> > > On Sat, Sep 5, 2020, 19:09 Wien2k User <wien2k.u...@gmail.com<mailto: > wien2k.u...@gmail.com>> wrote: > Dear Wien2k users, > > Is it more precise to use mBJ for the calculation of born effective charge > or gga is sufficient? (in a case where there is no comparison values) > _______________________________________________ > Wien mailing list > Wien@zeus.theochem.tuwien.ac.at<mailto:Wien@zeus.theochem.tuwien.ac.at> > > https://urldefense.com/v3/__http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien__;!!Dq0X2DkFhyF93HkjWTBQKhk!Fpbr4B1iYKYmN8y_CnPsog90yWsoj8ABLRarNwPfeAbkXYQflXhH_mF88q2TaPRV6qmLvw$ > SEARCH the MAILING-LIST at: > https://urldefense.com/v3/__http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html__;!!Dq0X2DkFhyF93HkjWTBQKhk!Fpbr4B1iYKYmN8y_CnPsog90yWsoj8ABLRarNwPfeAbkXYQflXhH_mF88q2TaPT-n2g2Aw$ > _______________________________________________ > Wien mailing list > Wien@zeus.theochem.tuwien.ac.at > > https://urldefense.com/v3/__http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien__;!!Dq0X2DkFhyF93HkjWTBQKhk!GdNcHpBDzmc0bKkfTPuHupsF84fQAHYEE4SpKCD6n0q9kD52LHuFkiYuzaf5syuIIoE38g$ > SEARCH the MAILING-LIST at: > https://urldefense.com/v3/__http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html__;!!Dq0X2DkFhyF93HkjWTBQKhk!GdNcHpBDzmc0bKkfTPuHupsF84fQAHYEE4SpKCD6n0q9kD52LHuFkiYuzaf5syu4hG8FVw$ >
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