Dear QE, I ran a vc-relax with the following specifications (16 atoms, 6 kinds (4 Al, 2Ti, 2Cr, 2 Fe, 3 Co, 3 Ni) :
&CONTROL calculation = "vc-relax", dt = 30.D0, / &SYSTEM ibrav = 1, A = 5.9726, nat = 16, ntyp = 6, ecutwfc = 12.D0, occupations = "smearing", smearing = "methfessel-paxton", degauss = 0.05D0, / &ELECTRONS conv_thr = 1.D-7, mixing_beta = 0.7D0, / &IONS ion_dynamics = "damp", pot_extrapolation = "second_order", wfc_extrapolation = "second_order", / &CELL cell_dynamics = 'bfgs' / ATOMIC_SPECIES Al 27 Al.pbe-n-rrkjus_psl.0.1.UPF Ti 48 Ti.pbe-sp-van_ak.UPF Cr 52 Cr.pbe-sp-van.UPF Fe 56 Fe.pbe-nd-rrkjus.UPF Co 59 Co.pbe-n-van_gipaw.UPF Ni 59 Ni.pbe-nd-rrkjus.UPF .... K_POINTS automatic 8 8 8 0 0 0 These are some of the total energies in the first scf step: .... -1167.37380454 -1167.37730282 -1167.37313462 -1167.32387998 -1167.36729923 -1167.36931830 -1167.36943509 -1167.37686298 -1167.37121766 -1167.36631842 -1167.36484431 -1167.31794482 -1167.35485093 -1167.36884054 -1167.36678740 -1167.36964606 -1167.35381941 -1167.29375341 -1167.31307315 -1167.30808057 It took 55 steps but still showed sign of convergence. I ended the calculation prematurely at this point, because it was taking too long. I'm just wondering if this is normal for such a system. Or something is going wrong, like &SYSTEM parameters. Thank you very much, Yantao Wu -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20130528/2289f505/attachment.html
