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 -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20081006/1ea29144/attachment-0001.htm
