[Pw_forum] Cell geometry optimization issue

[Arijan Aleksić]

Dear all,

I am working on geometry optimization for WTe2 (Tungsten(IV) telluride).
When running calculations, they failed to converge within limits in 100
iterations.

First I have increased cell parameters for 10-15% to check if there will
be any difference (also had big pressure). Next I went with reducing
mixing_beta in steps of 0.1 to check for any changes which yielded no good
results. And finally I used calculation = 'vc-relax' which gave even worse
results and could not optimize the cell.

I will accept any advice on what should be my next action in order to
succeed in getting optimization complete.

Here is the text from input file I used (version of Quantum Espresso is
5.2.1):

 &control
    calculation  = 'vc-relax',
    restart_mode = 'from_scratch',
    prefix       = 'wte2',
    tprnfor      = .true.,
    pseudo_dir   = '/home/aaleksic/Pseudo/',
    outdir       = '/home/aaleksic/wte2/tmp/',
 /

 &system
    ibrav     = 8,
    celldm(1) = 13,
    celldm(2) = 0.53846,
    celldm(3) = 2.15385,
    nat       = 24,
    ntyp      = 2,
    nbnd      = 74,
    ecutwfc   = 100.0,
 /

 &electrons
    mixing_beta = 0.1,
    conv_thr    = 1.0d-12,
 /

 &ions
 /

 &cell
 /

ATOMIC_SPECIES
 W   74.0   W.pbe-mt_fhi.UPF
 Te  52.0   Te.pbe-mt_fhi.UPF

ATOMIC_POSITIONS (crystal)
W   0.90050000000  0.5000000000  0.00000000000
Te  0.29410000000  0.5000000000  0.09650000000
Te  0.80020000000  0.0000000000  0.14000000000
W   0.54140000000  0.0000000000  0.98510000000
Te  0.35590000000  0.0000000000  0.34490000000
Te  0.85170000000  0.5000000000  0.38930000000
W   0.59950000000  0.5000000000  0.50000000000
Te  0.20590000000  0.5000000000  0.59650000000
Te  0.69980000000  0.0000000000  0.64000000000
W   0.95860000000  0.0000000000  0.48510000000
Te  0.14410000000  0.0000000000  0.84490000000
Te  0.64830000000  0.5000000000  0.88930000000
W   0.40050000000  0.5000000000  0.50000000000
Te  0.79410000000  0.5000000000  0.59650000000
Te  0.30020000000  0.0000000000  0.64000000000
W   0.04140000000  0.0000000000  0.48510000000
Te  0.85590000000  0.0000000000  0.84490000000
Te  0.35170000000  0.5000000000  0.88930000000
W   0.09950000000  0.5000000000  0.00000000000
Te  0.70590000000  0.5000000000  0.09650000000
Te  0.19980000000  0.0000000000  0.14000000000
W   0.45860000000  0.0000000000  0.98510000000
Te  0.64410000000  0.0000000000  0.34490000000
Te  0.14830000000  0.5000000000  0.38930000000



K_POINTS (automatic)
4 4 4 0 0 0

Thank you.

Best regards,
Arijan Aleksic,
University J.J.Strossmayer, Croatia.