[Pw_forum] symmetry problem in vc-relax

[Ezad Shojaee]

hi
i am doing vc-relax for TiO2 using symmetry-conserving algorithm ( 
cell_dynamics='damp-w' ) but still i have this message:

from checkallsym : error #         5
  not orthogonal operation

does anyone have any suggestion ?
this is the input file for pw.x   i am using :
&CONTROL
  calculation  = "vc-relax",
  restart_mode='from_scratch',
  prefix       = "TiO2",
  tstress = .true.
  tprnfor = .true.
  dt          =1,
  pseudo_dir   = "/root/pseudo",
  outdir       = "/root/tmp",
/
&SYSTEM
  ibrav     = 7,
  celldm(1) = 3.785,
  celldm(3) = 2.5136,
  nat       = 6,
  ntyp      = 2,
  ecutwfc   =40.0,

/
&ELECTRONS
  mixing_mode = 'plain'
  conv_thr    = 1.D-9,
  mixing_beta = 0.7,
/
&IONS
  ion_dynamics ='damp',
  pot_extrapolation='second-order',
  wfc_extrapolation='second-order',

/
&CELL
cell_dynamics='damp-w'
/
ATOMIC_SPECIES
Ti  1.00   Ti.vdb.UPF
O   1.00   O.vdb.UPF
ATOMIC_POSITIONS  { bohr }
Ti  0.00000000 -0.94625000 -1.18925000
Ti  0.00000000  0.94625000  1.18925000
O   0.00000000  0.94625000 -0.77634000
O   0.00000000 -0.94625000  0.77634000
O   1.89250000  0.94625000  1.60216000
O  -1.89250000 -0.94625000 -1.60216000
K_POINTS { automatic }
1  1  1     0 0 0

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