You can try larger ecutwfc=80. 2009/9/1 Pablo Aguado <paguado at gmail.com>
> Dear all, > > I'm doing some tests on the structural optimization with pw. I'm > currently testing with the tetragonal structure of PbTiO3, using the > following input: > > &control > calculation = 'vc-relax' > restart_mode = 'restart' > pseudo_dir = '/****/espresso-4.1/pseudo/' > outdir = '/***/tmp' > forc_conv_thr = 1d-3 > nstep = 50 > / > &system > ibrav=6 > celldm(1)=7.3699 > celldm(3)=1.04 > nat=5 > ntyp=3 > nbnd=28 > ecutwfc=30.0 > occupations = 'fixed' > / > &electrons > conv_thr = 1d-12, > mixing_beta=0.4, > / > &ions > ion_dynamics = 'bfgs' > bfgs_ndim = 5 > / > &cell > cell_dynamics = 'damp-pr' > press_conv_thr = 1.0d0 > cell_dofree = 'z' > / > ATOMIC_SPECIES > Pb 207.2 Pb.pz-d-van.UPF > Ti 47.867 Ti.pz-sp-van_ak.UPF > O 15.9994 O.pz-van_ak.UPF > ATOMIC_POSITIONS crystal > Pb 0.000 0.000 0.040 0 0 1 > Ti 0.500 0.500 0.520 0 0 1 > O 0.000 0.500 0.500 0 0 1 > O 0.500 0.500 0.000 0 0 1 > O 0.500 0.000 0.500 0 0 1 > K_POINTS automatic > 6 6 6 1 1 1 > > The relaxation is taking forever so I've checked the output and I've > found several steps where everything seems to be converged (notice I'm > only relaxing out-of-plane lattice vector) but the code keeps running. > An example: > > - Energy difference = 4e-7 > - Forces acting on atoms (Ry/au): > > atom 1 type 1 force = 0.00000000 0.00000000 0.00085679 > atom 2 type 2 force = 0.00000000 0.00000000 -0.00001779 > atom 3 type 3 force = 0.00000000 0.00000000 -0.00024617 > atom 4 type 3 force = 0.00000000 0.00000000 -0.00034665 > atom 5 type 3 force = 0.00000000 0.00000000 -0.00024617 > > Total force = 0.000988 Total SCF correction = 0.000002 > > total stress (Ry/bohr**3) (kbar) P= > -0.84 > -0.00001150 0.00000000 0.00000000 -1.69 0.00 0.00 > 0.00000000 -0.00001150 0.00000000 0.00 -1.69 0.00 > 0.00000000 0.00000000 0.00000591 0.00 0.00 0.87 > > Any idea of what's going on? > > Thank you very much > > Pablo > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > -- Y. C. Cheng Department of Physics Nanjing University Nanjing 210093 P. R. China Tel: 86-25-83592907 Email: yccheng.nju at gmail.com -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20090901/c33f9db2/attachment.htm
