Dear Masoud, thank you very much for your reply and suggestions. I haven't tried to use nspin=2 yet, but I will see if it helps. The distance between the atoms at the interface is around 2.5 angstrom. I will let you know if your suggestions solves the problem.
Thanks! BR, NV ???????????, 8 ?????? 2013, 16:03 +02:00 ?? Masoud Nahali <masoudnahali at gmail.com>: >Dear ?????? ?????? > > >Have you tried the calculation considering spin polarization, nspin=2 and >checking the convergence ? > >you can try a smaller degauss value using marzari-vanderbilt or gaussian too. >Please check the smearing energy contribution to your total energy. > > >Are the interface atoms in close distances from each other ? I mean 1.2-2.0 >angstrom for instance. If not and you put them at far distances from each >other you may relax a van der Waals interaction in which the pure DFT is weak. > >Do you really need such high amount of cutoff for energy and density ? > >I hope it helps. > > > > > > >? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? >Best Wishes, m > >? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?? >? > > >---------------------------------------- >Masoud Nahali >SUT >masoud.nahali at gmail.com ? >alum.sharif.edu/~m_nahali ? > > > > >On Mon, Apr 8, 2013 at 12:00 PM, ?????? ?????? wrote: >> >>? Hi everybody, >> >>I am trying to optimize the structure of an interface between metal and >>insulator but have difficulties with scf convergence. Here are the changes in >>energies during scf cycle: >>estimated scf accuracy < 17.58555120 Ry >>estimated scf accuracy < 14.17435383 Ry >>estimated scf accuracy < 2.05765892 Ry >>estimated scf accuracy < 2.09375911 Ry >>estimated scf accuracy < 1.37675281 Ry >>estimated scf accuracy < 0.42594758 Ry >>estimated scf accuracy < 0.29104539 Ry >>estimated scf accuracy < 0.51143695 Ry >>estimated scf accuracy < 0.18765814 Ry >>estimated scf accuracy < 0.92590998 Ry >>estimated scf accuracy < 0.93126088 Ry >>estimated scf accuracy < 0.44023978 Ry >>estimated scf accuracy < 0.33756785 Ry >>estimated scf accuracy < 0.34216551 Ry >>estimated scf accuracy < 0.36573444 Ry >>estimated scf accuracy < 0.29089342 Ry >>estimated scf accuracy < 0.29287805 Ry >>estimated scf accuracy < 0.16940331 Ry >>estimated scf accuracy < 0.17503222 Ry >>estimated scf accuracy < 0.09708451 Ry >>estimated scf accuracy < 0.07751341 Ry >>estimated scf accuracy < 0.06774554 Ry >>estimated scf accuracy < 0.15834930 Ry >>estimated scf accuracy < 0.12269823 Ry >>estimated scf accuracy < 0.12679734 Ry >>estimated scf accuracy < 0.08558475 Ry >>estimated scf accuracy < 0.04411767 Ry >>estimated scf accuracy < 0.04754042 Ry >> >>I found similar posts on the forum ?but it didn't solve the problem. I >>checked my structure with xcrysen...it seems to be ok. I am using USPP. >>Any help and suggestions would be greatly appreciated. >> >>Thanks >> >>Here is my input: >>&CONTROL >>title = interface , >>calculation = 'relax' , >>restart_mode = 'from_scratch' , >>wf_collect = .true. , >>outdir = 'interface/' , >>pseudo_dir = './' , >>prefix = 'interface' , >>lkpoint_dir = .true. , >>disk_io = 'high' , >>verbosity = 'high' , >>nstep = 100 , >>tstress = .false. , >>tprnfor = .true. , >>/ >>&SYSTEM >>ibrav = 8, >>celldm(1) = 9.3957, >>celldm(2) = 1.7321, >>celldm(3) = 6.0000, >>nat = 72, >>ntyp = 3, >>ecutwfc = 50 , >>ecutrho = 500 , >>nbnd = 500, >>occupations = 'smearing' , >>degauss = 0.025 , >>smearing = 'methfessel-paxton' , >>nspin = 1 , >>/ >>&ELECTRONS >>electron_maxstep = 200, >>conv_thr = 1.0d-6 , >>mixing_mode = 'local-TF' , >>mixing_beta = 0.1 , >>mixing_ndim = 8 , >>/ >>&IONS >>ion_dynamics = 'bfgs' , >>/ >>ATOMIC_SPECIES >>? BR, >> >>N V >-------------------------------------------------------------------------------------------------------------------- >_______________________________________________ >Pw_forum mailing list >Pw_forum at pwscf.org >http://pwscf.org/mailman/listinfo/pw_forum -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20130408/c4c217f4/attachment.html
