[Pw_forum] Error in vc-relax

[yukihiro_okuno at fujifilm.co.jp]

Dear PWSCF users.

I'm now doing vc-relax calculation, but met the difficulties of
conversence.

My conversence criterio is not too strict but the total force and stress is
not
conversed, and the calculation stopped by the message (defalt stress
criterio is
too strict to calculate ?)

I had change

 etot_conv_thr = 1.0D-4  to  etot_conv_thr = 1.0D-6 but the situation is
not changed.

The error message is



%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
     from checkallsym : error #         3
     not orthogonal operation

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

     stopping ...

The lattice we calaulation is tetragonal but the output  CELL_PARAMETRE
become like

CELL_PARAMETERS (alat)
   0.992118220   0.000000000   0.000000000
   0.000000000   0.992117943   0.000000000
   0.000000000   0.000000000   1.114913401

slightly orhogonal.

The force conversence is

   Total force =     0.001187     Total SCF correction =     0.000008
     Total force =     0.001134     Total SCF correction =     0.000012
     Total force =     0.001063     Total SCF correction =     0.000005
     Total force =     0.000977     Total SCF correction =     0.000002
     Total force =     0.000878     Total SCF correction =     0.000005
     Total force =     0.000705     Total SCF correction =     0.000056
     Total force =     0.000603     Total SCF correction =     0.000006
     Total force =     0.000586     Total SCF correction =     0.000012
     Total force =     0.000664     Total SCF correction =     0.000020
     Total force =     0.000634     Total SCF correction =     0.000110
     Total force =     0.000828     Total SCF correction =     0.000245
     Total force =     0.000789     Total SCF correction =     0.000015
     Total force =     0.000890     Total SCF correction =     0.000014
     Total force =     0.001005     Total SCF correction =     0.000007
     Total force =     0.001192     Total SCF correction =     0.000292
     Total force =     0.001165     Total SCF correction =     0.000021
     Total force =     0.001248     Total SCF correction =     0.000021
     Total force =     0.001264     Total SCF correction =     0.000044
     Total force =     0.001290     Total SCF correction =     0.000049
     Total force =     0.001293     Total SCF correction =     0.000054
     Total force =     0.001274     Total SCF correction =     0.000057
     Total force =     0.001235     Total SCF correction =     0.000057
     Total force =     0.001176     Total SCF correction =     0.000055
     Total force =     0.001102     Total SCF correction =     0.000051
     Total force =     0.001002     Total SCF correction =     0.000041
     Total force =     0.000977     Total SCF correction =     0.000074
     Total force =     0.001074     Total SCF correction =     0.000038
     Total force =     0.001172     Total SCF correction =     0.000072
     Total force =     0.001191     Total SCF correction =     0.000165
     Total force =     0.001256     Total SCF correction =     0.000016
     Total force =     0.001272     Total SCF correction =     0.000018
     Total force =     0.001412     Total SCF correction =     0.000320
     Total force =     0.001330     Total SCF correction =     0.000040
     Total force =     0.001375     Total SCF correction =     0.000018

and The stress is

   entering subroutine stress ...
          total   stress  (Ry/bohr**3)                   (kbar)     P=
-1.83
     entering subroutine stress ...
          total   stress  (Ry/bohr**3)                   (kbar)     P=
-1.63
     entering subroutine stress ...
          total   stress  (Ry/bohr**3)                   (kbar)     P=
-1.39
     entering subroutine stress ...
          total   stress  (Ry/bohr**3)                   (kbar)     P=
-1.11
     entering subroutine stress ...
          total   stress  (Ry/bohr**3)                   (kbar)     P=
-0.80
     entering subroutine stress ...
          total   stress  (Ry/bohr**3)                   (kbar)     P=
-0.47
     entering subroutine stress ...
          total   stress  (Ry/bohr**3)                   (kbar)     P=
-0.53
     entering subroutine stress ...
          total   stress  (Ry/bohr**3)                   (kbar)     P=
-0.42
     entering subroutine stress ...
          total   stress  (Ry/bohr**3)                   (kbar)     P=
-0.26
     entering subroutine stress ...
          total   stress  (Ry/bohr**3)                   (kbar)     P=
-0.09
     entering subroutine stress ...
          total   stress  (Ry/bohr**3)                   (kbar)     P=
0.05
     entering subroutine stress ...
          total   stress  (Ry/bohr**3)                   (kbar)     P=
0.19
     entering subroutine stress ...
          total   stress  (Ry/bohr**3)                   (kbar)     P=
0.40
     entering subroutine stress ...
          total   stress  (Ry/bohr**3)                   (kbar)     P=
0.52
     entering subroutine stress ...
          total   stress  (Ry/bohr**3)                   (kbar)     P=
0.69
     entering subroutine stress ...
          total   stress  (Ry/bohr**3)                   (kbar)     P=
0.93

My Input file is like this,

&control
    calculation  = 'vc-relax',
    restart_mode = 'from_scratch',
    pseudo_dir   = '../pseudo/',
    outdir       = './',
    prefix='SystemName'
    nstep = 100
    etot_conv_thr = 1.0D-4
    forc_conv_thr = 1.0D-3
    dt = 80.0
    tstress = .true.
    tprnfor = .true.
  /
 &system
    ibrav=6
    celldm(1)=6.86225965271
    celldm(3)=1.0806385896
    nat=5
    ntyp=3
    nbnd=26
    ecutwfc=60.0
    ecutrho = 600.0
    occupations = 'fixed'
    degauss=0.00
 /
 &electrons
    conv_thr = 1e-10,
    mixing_beta=0.3,
 /
&IONS
 bfgs_ndim=3
 pot_extrapolation = "second_order"
 wfc_extrapolation = "second_order"
/
&CELL
  cell_dynamics  = 'damp-w',
  press = 0.0
  wmass = 0.1
/


How should treat such a conversence difficulties and erro message?

Sincerely.

Yukihiro Okuno.