Hi, Thanks a lot for your reply. I'll give it a try with constraints but I'm also wondering should the other SCF's not have higher energy than the equilibrium angle regardless of them being optimized with a constraint? I mean if the structure is originally relax (which it is) then one expects other near equilibrium structures to have higher energies. Am I wrong there?
Regards, Arash On 2017-04-17 20:49, Marton wrote: > Hi S. Arash Sheikholeslam, > > I'm not sure this is the problem but from what you described my > understanding is that when you scan that angle manually you don't > optimize the other degrees of freedom. On the other hand, when you > relax the molecule, all degrees of freedom are relaxed. This > discrepancy between the two approaches could explain the behavior you > are seeing. If you are interested in doing the manual optimization, > you could try to relax the molecule with a constraint on the angle > with card CONSTRAINTS. > > HTH > Marton Voros > > -- > Materials Science Division > Argonne National Laboratory > > On Mon, Apr 17, 2017 at 8:55 PM, sarashs <[email protected]> wrote: > >> Hi, >> >> I've posted this question before but wasn't successful in getting >> an >> answer. I have a molecule ((OH)3ZrOSi(OH)3) and I want to find the >> equilibrium angle of ZrOSi. The equilibrium angle that I get with a >> "relax" calculation differs a lot from the result I get by >> increasing >> the angle and performing an "SCF" calculation. I tried various >> things >> including increasing the ecutwfc and ecutrho and fixing the number >> of >> bands for both calculations but had no success. Is there any chance >> someone can tell me what I'm missing? >> >> Here's a sample code my code: >> >> &CONTROL >> calculation = "scf", >> outdir = "outputs", >> prefix ="ZrSi3", >> restart_mode="from_scratch" >> pseudo_dir = "pseudos", >> / >> &SYSTEM >> nosym = .TRUE., >> ibrav = 0, >> nat = 15, >> ntyp = 4, >> ecutwfc = 600, >> ecutrho = 6000, >> vdw_corr = "grimme-d2", >> / >> &ELECTRONS >> conv_thr = 1.D-11, >> mixing_beta = 0.5D0, >> / >> ATOMIC_SPECIES >> O 15.9994 O.pz-mt.UPF >> H 1.00794 H.pz-vbc.UPF >> Si 28.0855 Si.pz-vbc.UPF >> Zr 91.224 Zr.pz-hgh.UPF >> ATOMIC_POSITIONS { angstrom } >> H -0.217652040 2.144165004 -0.967842103 >> O -0.644926428 1.299751587 -1.173517450 >> H -0.763682000 -2.102234442 -0.637701677 >> O -0.631971073 -1.266428593 -1.106959840 >> H -2.244617658 0.059203828 1.041286276 >> O -1.287708239 0.028876445 1.183017241 >> Si -0.341076411 0.043743634 -0.163179170 >> O 1.183131599 0.097692502 0.401792709 >> Zr 2.959296806 0.743741575 0.268340451 >> H 3.161927401 3.483669731 0.077078720 >> O 2.777805281 2.601338899 0.023924414 >> H 4.228044154 0.110551898 2.670358608 >> O 4.003457303 0.315517992 1.757071324 >> H 3.597999032 -0.225640653 -2.168546302 >> O 3.766434111 -0.029092443 -1.238766538 >> K_POINTS { gamma } >> CELL_PARAMETERS { angstrom } >> 13 0 0 >> 0 13 0 >> 0 0 13 >> >> Regards, >> >> S. Arash Sheikholeslam >> PhD candidate at electrical engineering department, University of >> British columbia >> _______________________________________________ >> Pw_forum mailing list >> [email protected] >> http://pwscf.org/mailman/listinfo/pw_forum [1] > > > > Links: > ------ > [1] http://pwscf.org/mailman/listinfo/pw_forum > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum _______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
