[Pw_forum] Interferences between symmetry generation and "ecutrho" value
Stefano de Gironcoli
degironc at sissa.it
Tue Aug 25 17:19:43 CEST 2009
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 Orléans Cedex 2, France
>
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