Dear Y. M. Qian, you may try to reduce alpha_mix to 0.3/0.4 and restart your calculation, because if you use a very high value of alpha_mix and you are near the minima, it may be possible that that the new potential overshoot the minimum.
Prasenjit. 2008/10/6 yumin qian <yuminqian at gmail.com> > I did a phonon calculation with the A-spin type CaCrO3 system , the > system is Pbnm structure , in the unit cell there are 20 atoms and the Cr > atoms are spin parallel in a-b plane and anti-parallel along c axis . > After a scf calculation by pw.x whit a k-point mesh of 6?6?4 I choose a q > point mesh of 4?4?4 but the thresh cann't be reached and ddv_scf|^2 > dangling around 1.0E-7 ,I use the alpha_mix = 0.700 , how to make it > converge for such large system? > > -- > Sincerely Y. M. Qian > Lab.of Condensed Matter Theory and Materials Computation > Institute of Physics > Chinese Academy of Sciences > Tel: + 8610 8264 9147 > E-Mail:yuminqian at gmail.com <E-Mail%3Ayuminqian at gmail.com> > P.O.Box 603 Beijing 100190 > China > > > _______________________________________________ > 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/20081006/9a9f1f50/attachment.htm
