this issue has been discussed several times in this forum. please check the archive looking for "fractional translation" best regards, Stefano de Gironcoli - SISSA and DEMOCRITOS
Sylvian Cadars wrote: > Hi, > > Playing with test files of the GIPAW_example, and more specifically the > basic SCF "quartz.scf.in" calculation, I found the symmetry generation > would fail for certain values of "ecutrho" (see list of the tests > conducted below). Importantly, problems can occur even though one sticks > to the default value (=4*ecutwfc). These errors seem to be independent > of the ecutwfc value, at least this is what my tests suggest. > Is this a known issue? Where does it come from? Is it predictable and > avoidable? > Thanks. > All the best. > > Sylvian. > > --------------------------- > ecutwfc ecutrho result > --------------------------- > 70 140 failed > 70 210 OK > 70 280 OK (=default) > 70 300 OK > 70 420 OK > 70 600 failed > 150 600 failed (=default) > 150 - failed (ecutrho=600) > 105 - OK (ecutrho=420) > 200 800 OK > 200 1200 OK > -------------------------- > > The error messages that occur are the following: > Max angular momentum in pseudopotentials (lmaxx) = 3 > warning: symmetry operation # 7 not allowed. fractional translation: > 0.0000000 0.0000000 -0.3333333 in crystal coordinates > warning: symmetry operation # 8 not allowed. fractional translation: > 0.0000000 0.0000000 0.3333333 in crystal coordinates > warning: symmetry operation # 11 not allowed. fractional translation: > 0.0000000 0.0000000 0.3333333 in crystal coordinates > warning: symmetry operation # 12 not allowed. fractional translation: > 0.0000000 0.0000000 -0.3333333 in crystal coordinates > > And 2 symmetry operations are found instead of 6 when everything works > properly. > 2 Sym.Ops. (no inversion) > > > For convenience, here is a typical input file that fails: > > &CONTROL > calculation = 'scf' , > restart_mode = 'from_scratch' , > outdir = '/home/sc/espresso_tmp' , > pseudo_dir = '/home/sc/PWscf/PseudoPotentials/PBE_090707/' , > / > &system > ibrav = 0 > celldm(1) = 1. > nat = 9 > ntyp = 2 > ecutwfc = 150 > ecutrho = 600 > / > &ELECTRONS > electron_maxstep = 100 > conv_thr = 5.0e-8 > startingpot = 'atomic' > startingwfc = 'atomic' > mixing_mode = 'plain' > mixing_beta = 0.7 > diagonalization = 'david' > diago_thr_init = 1.e-2 > / > ATOMIC_SPECIES > Si 28.0855000 SiPBE_nc.UPF > O 15.9994000 OPBE_nc.UPF > > ATOMIC_POSITIONS crystal > Si 0.4701 0.0000 0.3333333333 > Si 0.0000 0.4701 0.6666666667 > Si -0.4701 -0.4701 0.0000000000 > O 0.4139 0.2674 0.2144 > O -0.2674 0.1465 0.5477333333 > O -0.1465 -0.4139 0.8810666667 > O 0.2674 0.4139 -0.2144 > O 0.1465 -0.2674 0.4522666667 > O -0.4139 -0.1465 0.1189333333 > > CELL_PARAMETERS hexagonal > 4.642775480 -8.041523019 0.000000000 > 4.642775480 8.041523019 0.000000000 > 0.000000000 0.000000000 10.213406856 > > K_POINTS automatic > 2 2 2 1 1 1 > > > *Dr. Sylvian CADARS* > CEMHTI-CNRS > 1D, Av. de la Recherche Scientifique > 45071 Orl?ans Cedex 2, France > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum >
