[Pw_forum] Error during vc-relax process

[saswata halder]

Dear all,

I have been trying to carry out the vc-relax of double perovskite
Sr2MgWO6 with cubic Fm3m symmetry. The calculation stops showing the
following error.

"from checkallsym : error #         1
     some of the original symmetry operations not satisfied ."

the input file is provided below:

 &CONTROL
    calculation='vc-relax',
    restart_mode='from_scratch',
    prefix='ST'
    pseudo_dir = '/home/quantum/quantum/potentials/',
    outdir='./'
    tstress=.true.
    tprnfor=.true.
    verbosity='high'
    wf_collect=.true.
    nstep=1000
    etot_conv_thr=1.0D-8
    forc_conv_thr=1.0D-6
    press_conv_thr=0.2D0
    disk_io='high'
 /
 &SYSTEM
    ibrav = 2, celldm(1) =15.0329, nat = 10, ntyp= 4,
    ecutwfc = 80.0, ecutrho=800, occupations='fixed',
    smearing='gaussian', degauss=0.07
 /
 &ELECTRONS
    diagonalization='cg',
    mixing_mode='plain',
    mixing_beta = 0.7D0
    conv_thr =  1.0D-9
    electron_maxstep=1000
 /
&IONS
    ion_dynamics='bfgs'
/
&CELL
    cell_dynamics='bfgs',
    press=2.0,
    press_conv_thr=0.5,
/
ATOMIC_SPECIES
 Sr  87.620  Sr.pbe-mt_fhi.UPF
 Mg  24.305  Mg.pbe-mt_fhi.UPF
 W  183.840  W.pbe-mt_fhi.UPF
 O   15.999  O.pbe-mt_fhi.UPF
ATOMIC_POSITIONS crystal
 Sr 0.25  0.25  0.25  0 0 0
 Sr 0.75  0.75  0.75  0 0 0
 Mg 0.50  0.00  0.00  0 0 0
 W  0.00  0.00  0.00  0 0 0
 O  0.245 0.00  0.00  1 0 0
 O  0.755 0.00  0.00  1 0 0
 O  0.00  0.245 0.00  0 1 0
 O  0.00  0.755 0.00  0 1 0
 O  0.00  0.00  0.245 0 0 1
 O  0.00  0.00  0.755 0 0 1
K_POINTS automatic
 7 7 7   1 1 1


It would be helpful if you can please explain what the error means and
suggest how I can fix it so that I may carry out the phonon
calculations.

Thanking you in advance,

Saswata Halder.

Senior Research Fellow,
Bose Institute.
Kolkata.