Hi Yang, Here are a few general suggestions:
(1) Check the convergence wrt to vacuum (distance between periodic images). In ur case it seems too small to me, as a result of which the periodic images are interacting. I think this is specially important for ur case because ur having an external electric field. (2) check convergence wrt ecutrho & ecutwfc. Ususally ecutrho is 10-12 times ecutwfc. (probably ur wave fn is not converged) (3) a value of mixing beta=0.05 is too low. Such a low value often implies that you don't move the electrons at all......hence its not very effective........according to my experience, at least for cal. without electric field, a value of 0.2-0.3 works well. (4) Also you are doing a slab cal. and usually either a few layers at the bottom or a few in the middle are kept fixed (although this should not affect ur electronic minimization). With regards, Prasenjit. (5) ur value of conv_thr seem too high.....at least u should use the default value. But I would suggest u to use something of the order of 10^-8. 2009/4/16 ?? <sunyang198498 at gmail.com> > Thanks for your advice, Deng. > > Yang > > 2009/4/15 ?? <panda.deng.pan at gmail.com>: > > maybe the ecutwfc value is small. > > > > _______________________________________________ > > Pw_forum mailing list > > Pw_forum at pwscf.org > > http://www.democritos.it/mailman/listinfo/pw_forum > > > > > > > > -- > University of Nebraska at Lincoln > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > -- PRASENJIT GHOSH, POST-DOC, ROOM NO: 265, MAIN BUILDING, CM SECTION, ICTP, STRADA COSTERIA 11, TRIESTE, 34104, ITALY PHONE: +39 040 2240 369 (O) +39 3807528672 (M) -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20090416/e3043d76/attachment.htm