[Pw_forum] vc-relax lattice constance optimzition

[Hong Tang]

Hi, All:

I am very grateful somebody can help me the following problem.

I am trying to use QE to do Si  crystal lattice optimization. please see
the input of my file.  However, after calculations, I sue grep -n "volume"
Si.rx.out , I got results that always show the volume of the unit cell
doesn't change.
[hongtang at login3 results]$ grep -n "volume" Si.rx.out
39:     unit-cell volume          =     265.3020 (a.u.)^3
1812:     new unit-cell volume =    265.30200 a.u.^3 (    39.31370 Ang^3 )
3146:     new unit-cell volume =    265.30200 a.u.^3 (    39.31370 Ang^3 )
4462:     new unit-cell volume =    265.30200 a.u.^3 (    39.31370 Ang^3 )
5776:     new unit-cell volume =    265.30200 a.u.^3 (    39.31370 Ang^3 )
5807:     unit-cell volume          =     265.3020 (a.u.)^3
________________________________________________

input
&CONTROL
  calculation = "vc-relax",
  pseudo_dir  = "/home/hongtang/tmqe6.0/pseudo",
  prefix      = "Si",
  outdir      = "/home/hongtang/tmqe6.0/tempdir",
  dt          = 100,
  verbosity   = 'high',
  tstress     = .true.
  tprnfor     = .true.
  nstep       = 900,
  etot_conv_thr = 1.D-5,
  forc_conv_thr  = 1.D-4,
/
&SYSTEM
  ibrav       = 2,
  celldm(1)   = 10.2D0,
  nat         = 2,
  ntyp        = 1,
  ecutwfc     = 60.D0,
  nosym = .true.
/
&ELECTRONS
  conv_thr   = 1.D-7,
  mixing_beta = 0.7D0,
  electron_maxstep  = 300
/
&IONS
   bfgs_ndim      = 1,
   trust_radius_max = 1.0D0,
   trust_radius_ini  = 0.6D0,
   trust_radius_min = 0.1D0,
/
&CELL
  cell_dynamics = 'bfgs',
/
ATOMIC_SPECIES
Si 28.09 Si.tpss-mt.UPF
ATOMIC_POSITIONS
Si 0.00 0.00 0.00
Si 0.25 0.26 0.24
K_POINTS {automatic}
7 7 7 0 0 0
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20170627/7863beae/attachment.html>