[Pw_forum] phosphorene monolayer

[Gautam Gaddemane]

Thank you so much Vahid. I have a question though..how did you get the
initial CELL_PARAMETERS ? I obtained the initial cell and atomic parameters
from bulk.

GAUTAM GADDEMANE
DEPARTMENT OF MATERIALS SCIENCE AND ENGINEERING
UNIVERSITY OF TEXAS AT DALLAS

On Thu, Oct 5, 2017 at 4:19 PM, Vahid Askarpour <vh261281 at dal.ca> wrote:

> Hi Gautam,
>
> The following relaxation input worked for me:
>
> BP
> 2D
> &control
>     calculation='vc-relax'
>     restart_mode='from_scratch',
>     prefix='BP'
>     pseudo_dir='./'
>     verbosity='high'
>     tprnfor=.true.
>     tstress=.true.
>     etot_conv_thr=1.0e-06
>     forc_conv_thr=1.0e-05
> /
> &system
>     ibrav=0,
>     nat= 4, ntyp= 1
>     ecutwfc = 50, ecutrho=200,
>     occupations = 'fixed' ,
> /
> &electrons
>     diagonalization='cg'
>     conv_thr = 1.0e-12
>     mixing_beta = 0.7
>     electron_maxstep = 500
>     mixing_mode = 'plain'
> /
> &IONS
>   ion_dynamics = 'bfgs'
>   pot_extrapolation='atomic'
>   wfc_extrapolation='atomic'
> /
> &CELL
>   cell_dynamics = 'bfgs'
>   wmass=0.002
>   cell_factor=2.0
>   cell_dofree='xyz'
> /
> ATOMIC_SPECIES
> P  30.97376  P.pbesol-n-kjpaw_psl.0.1.UPF
>
> K_POINTS {automatic}
> 14 12 1  0 0 0
>
> CELL_PARAMETERS (angstrom)
>    4.429539231   0.000000000   0.000000000
>    0.000000000   3.279402120   0.000000000
>    0.000000000   0.000000000  31.941846246
>
> ATOMIC_POSITIONS (crystal)
> P        0.001152971   0.000000000   0.015264978
> P        0.335395312   0.499999800   0.015264292
> P        0.501101273   0.499999800   0.081335135
> P        0.835350444   0.000000000   0.081335495
>
> Best,
>
> Vahid
>
> Vahid Askarpour
> Department of Physics and Atmospheric Science
> Dalhousie University,
> Halifax, NS, Canada
>
> > On Oct 5, 2017, at 4:45 PM, Gautam Gaddemane <gautamg88 at gmail.com>
> wrote:
> >
> > Dear All,
> >
> > I am trying to calculate the bands tructure for monolayer phosphorene
> and I am just a week old in using quantum espresso.
> > From the bulk unit cell I prepared an input file to relax the structure
> but I was not able to get a good lattice constant nor a good band gap. It
> would be very helpful if someone would guide me in this procedure.
> > I have attahced the file I used to relax in this email
> >
> >
> > &CONTROL
> >   calculation='vc-relax',
> >   outdir='./',
> >   prefix='calc',
> >   pseudo_dir='./',
> >   verbosity='high',
> > /
> >
> > &SYSTEM
> >   ibrav=0,
> >   celldm(1)= 8.276999830d0
> >   nat=4,
> >   ntyp=1,
> >   ecutwfc=60,
> >   ecutrho=360,
> >   input_dft='lda',
> >   occupations='smearing',
> >   smearing='mv',
> >   degauss=0.005d0,
> > /
> >
> > &ELECTRONS
> >   conv_thr=1d-06,
> >   mixing_beta=0.7d0,
> > /
> > &IONS
> >   ion_dynamics='bfgs'
> > /
> >
> > &CELL
> >   cell_dynamics='bfgs'
> >   cell_dofree='2Dshape'
> > /
> > ATOMIC_SPECIES
> >   P 30.973800d0 P.pw-mt_fhi.UPF
> >
> > ATOMIC_POSITIONS {crystal}
> >
> >  P  0.090000004         0.000000000         0.050195117
> >  P  0.909999967         0.000000000         0.949804902
> >  P  0.590000033         0.500000000         0.949804902
> >  P  0.409999996         0.500000000         0.050195117
> >
> > K_POINTS {automatic}
> >
> >   12 12 1 0 0 0
> >
> > CELL_PARAMETERS {alat}
> >
> >      1.0000000000000000    0.0000000000000000    0.0000000000000000
> >      0.0000000000000000    0.7511415530000000    0.0000000000000000
> >      0.0000000000000000    0.0000000000000000   4.68036529200000000
> >
> >
> > thank you
> > Gautam
> >
> > GAUTAM GADDEMANE
> > DEPARTMENT OF MATERIALS SCIENCE AND ENGINEERING
> > UNIVERSITY OF TEXAS AT DALLAS
> > _______________________________________________
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> > Pw_forum at pwscf.org
> > http://pwscf.org/mailman/listinfo/pw_forum
>
>
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