Dear Sonu Kumar, in general this warning means that the forces you are computing are not very accurate, BUT relatively to their absolute value. Here, the absolute value of the force is very small so even a tiny SCF correction appears large, so the warning. You can safely ignore it because there's no harm in missing forces by 25% when they are negligible. Notice that how large a 'negligible' force depends on you and the system under investigation. In my experience this situation is not unfrequent at the end of the optimization process. I expect you could get accurate results in terms of coordinates and total energy also with a bit larger scf threshold (1d-8?).
Guido Il 12/23/2011 05:47 AM, Sonu Kumar ha scritto: > Dear all QE users, > > During optimization, i got following message: > > Total force = 0.000004 Total SCF correction = 0.000001 > SCF correction compared to forces is too large, reduce conv_thr > > Total force is less than total scf correction. Then why the message > is contradicting? I used conv threshold for scf=1.0d-10. > > Thank you. > > regards, > > ========================================== > Sonu Kumar > Phd Student,Physics Department > Indian Institute of Technology ,Delhi-110016, India > web:-http://www.iitd.ac.in/ > ========================================== > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > -- Guido Fratesi Dipartimento di Scienza dei Materiali Universita` degli Studi di Milano-Bicocca via Cozzi 53, 20125 Milano, Italy
