Hi, Dr.A.Zhako Titarenko and other users, You mean the mixing betta. My value for mixing betta is 0.05, is it still too high?
Thank you in advance. Yang 2009/4/15 AZGlobal <azgre at azgre.com>: > Usually oscillating ?SCF process is result of some flat band ?(lots of > low-dispersion bands in Pd near Ef) flipping below/above Ef from > iteration to iteration, when you iterate. The cure is smaller admixing. > Takes much more processor time, but you can iterate for weeks with too > big admix and no result. Hope this helps. >> Dear All, >> >> When I do the calculation of the electronic structure of slab >> Palladium under the external electric field, >> convergence problems appear. The typical problem is that the estimated >> scf accuracy value drop down >> down and bounce back. It seems that the calculation does not know >> where the system would go for >> minimizing the total energy. The electric field that I applied is >> saw-tooth like one. I tried many things like >> increasing the mixing_ndim, decreasing the mixing_betta to 0.1, adding >> empty bands changing the mixing >> mode and even increase the degauss. But, none of them would work for >> the scf accuracy oscillating problem. >> Below is the input file. Any suggestion is highly appreciated. >> >> >> >> >> &control >> ? ? calculation='scf' >> ? ? restart_mode='from_scratch', >> ? ? pseudo_dir = '$PSEUDO_DIR/', >> ? ? outdir='$TMP_DIR/' >> ? ? prefix='Pd' >> ? ? tefield = .true. >> ? ? dipfield = .true. >> ? ? nstep = 300 >> >> ?/ >> ?&system >> ? ? ibrav = 6 >> ? ? celldm(1) = 7.3331 >> ? ? nspin = 2 >> ? ? celldm(3) = 4.5 >> ? ? edir = 3 >> ? ? emaxpos=0.72 >> ? ? eopreg=0.28 >> ? ? eamp = -0.001944 >> ? ? starting_magnetization=0.05 >> ? ? ntyp = 1 >> ? ? nat= 14 >> ? ? ecutwfc = 25.0, >> ? ? ecutrho = 500.0, >> ? ? occupations='smearing', >> ? ? degauss=0.2 >> ? ? nbnd=160 >> ?/ >> >> ?&electrons >> ? ? conv_thr = 1.0e-4 >> ? ? mixing_mode='local-TF' >> ? ? mixing_beta = 0.05 >> ? ? mixing_ndim = 12 >> >> ?/ >> ATOMIC_SPECIES >> ?Pd ?100 ?Pd.pz-nd-rrkjus.UPF >> ATOMIC_POSITIONS >> Pd ? ? ? 0.500000000 ? 0.000000000 ?-1.496126804 >> Pd ? ? ? 0.000000000 ? 0.500000000 ?-1.496126804 >> Pd ? ? ? 0.000000000 ? 0.000000000 ?-1.002542052 >> Pd ? ? ? 0.500000000 ? 0.500000000 ?-1.002542051 >> Pd ? ? ? 0.500000000 ? 0.000000000 ?-0.501470158 >> Pd ? ? ? 0.000000000 ? 0.500000000 ?-0.501470158 >> Pd ? ? ? 0.000000000 ? 0.000000000 ? 0.000000000 >> Pd ? ? ? 0.500000000 ? 0.500000000 ? 0.000000000 >> Pd ? ? ? 0.500000000 ? 0.000000000 ? 0.501470158 >> Pd ? ? ? 0.000000000 ? 0.500000000 ? 0.501470158 >> Pd ? ? ? 0.000000000 ? 0.000000000 ? 1.002542052 >> Pd ? ? ? 0.500000000 ? 0.500000000 ? 1.002542051 >> Pd ? ? ? 0.500000000 ? 0.000000000 ? 1.496126804 >> Pd ? ? ? 0.000000000 ? 0.500000000 ? 1.496126804 >> >> >> >> >> K_POINTS (automatic) >> ?8 8 1 0 0 0 >> >> >> >> > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > -- University of Nebraska at Lincoln
