Kamal, The scf will try to optimize the total energy. Once the energy is optimized, the magnetic moment should stop oscillating.
Each step the program prints this line: "estimated scf accuracy: XXXXX". If XXXXX is becoming smaller over time, the calculation is converging. If not, then you can try other beta values, as discussed here: http://www.quantum-espresso.org/user_guide/node64.html#SECTION000137020000000000000 Just looking at the magnetization before the system gets self-consistent is pointless, since all kind of values will show up. A little idea that might help: be sure that you have enough kpoints. 5x5x5 can be too few for many purposes. I'd give it a try with, say, 11x11x11 to see if the final magnetization (after the scf is concluded) changes. Best regards, Giovani M. Faccin CPPP / UFMS - Brazil 2012/3/2 <ksaha at physics.udel.edu> > Dear Users, > > I am running scf-iterations of a ferrimagnetic yttrium iron garnet (bcc > primitive cell with 80 atoms) system and find that the convergence of > magnetic moment is very slow. Can you any suggest me how to accelerate the > overall convergence? Please see the last a few steps of magmom of the > 100-scf steps: > > total magnetization = 78.61 Bohr mag/cell > total magnetization = 78.79 Bohr mag/cell > total magnetization = 78.78 Bohr mag/cell > total magnetization = 78.91 Bohr mag/cell > total magnetization = 79.25 Bohr mag/cell > total magnetization = 79.17 Bohr mag/cell > total magnetization = 79.22 Bohr mag/cell > total magnetization = 79.06 Bohr mag/cell > total magnetization = 79.08 Bohr mag/cell > total magnetization = 79.10 Bohr mag/cell > total magnetization = 79.12 Bohr mag/cell > total magnetization = 79.09 Bohr mag/cell > total magnetization = 79.15 Bohr mag/cell > total magnetization = 79.23 Bohr mag/cell > total magnetization = 79.17 Bohr mag/cell > total magnetization = 79.47 Bohr mag/cell > total magnetization = 79.45 Bohr mag/cell > total magnetization = 79.15 Bohr mag/cell > total magnetization = 81.33 Bohr mag/cell > total magnetization = 82.16 Bohr mag/cell > total magnetization = 82.24 Bohr mag/cell > total magnetization = 82.32 Bohr mag/cell > total magnetization = 82.53 Bohr mag/cell > total magnetization = 84.89 Bohr mag/cell > total magnetization = 82.93 Bohr mag/cell > total magnetization = 78.05 Bohr mag/cell > total magnetization = 84.82 Bohr mag/cell > total magnetization = 84.32 Bohr mag/cell > total magnetization = 84.69 Bohr mag/cell > total magnetization = 85.38 Bohr mag/cell > total magnetization = 87.34 Bohr mag/cell > > Also, here is the part of the script which you may want to look at: > > &system > ibrav = 3, > celldm(1) = 23.24362966, ! = a, in Bohr > nat= 80, > ntyp= 3, > nspin=2, > starting_magnetization(1)=0.0, > starting_magnetization(2)=2.60, > starting_magnetization(3)=0.0, > occupations='smearing', > smearing='mp', > degauss=0.02, > ecutwfc =30, > ecutrho =240 > / > &electrons > electron_maxstep = 400, > diagonalization='david', > conv_thr = 1.0e-6, > mixing_beta = 0.05, > !mixing_ndim = 6 > mixing_ndim = 10 > / > ATOMIC_SPECIES > Y 88.90585 Y.pbe-nsp-van.UPF > Fe 55.84500 Fe.pbe-sp-van_mit.UPF > O 15.99940 O.pbe-van_ak.UPF > . > . > . > K_POINTS automatic > 5 5 5 1 1 1 > > Many thanks for your comments and suggestions, > > Regards, > Kamal > > ========================================================== > Kamal K. Saha > Department of Physics and Astronomy > University of Delaware > Newark, DE 19716-2570 > Phone: (302) 831-8519, Fax: (302) 831-1637 > > http://web.physics.udel.edu/about/directory/postdoc/kamal-k-saha > ========================================================== > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20120302/9e98cd7b/attachment.htm
