[QE-users] relaxation under the external saw-like electrical potential

[Sahar Izadi]

Dear all,
I am interested in the paper: https://doi.org/10.1103/PhysRevB.97.054416
I would like to follow its results. At the first step, I need to relax the
crystal structure under the external saw-like electrical potential by QE
package. According to the paper, the bond angles of Cr-I-Cr in the top and
bottom plane of the relaxed structure, referred by theta1 and theta2 have a
difference about 2 degrees at 1 eV/nm. But my DFT calculations show that
the electric field does not change the structure geometry!
Here you can find my input file? If I have forgotten something, please let
me know.

Best regards,
Sahar Izadi
Postdoc researcher at IPM
----------------------------------------
&CONTROL
  calculation='vc-relax',
  outdir='./',
  prefix='relE',
  pseudo_dir='./',
  tefield = .true.,
  dipfield = .true.,
  wf_collect=.true.,
  tprnfor=.true.,
  tstress=.true.,
  etot_conv_thr=1d-6,
  forc_conv_thr=1d-4,
/
&SYSTEM
  ibrav=4,
  celldm(1)=13.3180905273d0, celldm(3)=5.675666855383d0
  nat=8,
  ntyp=2,
  ecutwfc=80,
  occupations='smearing',
  smearing='mv',
  degauss=0.01d0,
  nspin   = 2
  starting_magnetization(1)=1,
  edir=  3
  eamp= 0.006 ! corresponding to 3.09 eV/nm
  emaxpos=0.95d0,
  eopreg=0.05d0,
/

&ELECTRONS
  conv_thr=1d-10,
  electron_maxstep=500,
  mixing_beta=0.7d0,
/

&IONS
  ion_dynamics='bfgs',
  upscale=220,
/

&CELL
  cell_dynamics='bfgs',
  press=0.0d0,
  press_conv_thr=0.05d0,
/


ATOMIC_SPECIES
  Cr 51.996100d0  Cr.pbe-n-nc.UPF
  I  126.904000d0 I.pbe-n-nc.UPF

ATOMIC_POSITIONS {crystal}

  Cr   0.7437072547d0   0.1666691480d0   0.4999996536d0
  Cr   0.4103708485d0   0.5000018526d0   0.4999996885d0
   I   0.0770490950d0   0.4748440602d0   0.4603865190d0
   I   0.0770444830d0   0.1918398526d0   0.5396142354d0
   I   0.4355397493d0   0.1918537239d0   0.4603871637d0
   I   0.4355307864d0   0.8333206653d0   0.5396123221d0
   I   0.7185253232d0   0.4748317887d0   0.5396124224d0
   I   0.7185332444d0   0.8333308520d0   0.4603857646d0

K_POINTS {automatic}
  8 8 1 0 0 0
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20200219/b2b945ac/attachment.html>