[Pw_forum] Electronic structure calculation of graphene as a spintronic material using espresso-4.2)

[Rahen Badsha]

Dear QE PWscf users,
I calculated scf, nscf,bands,plotband , dos and spin polarization of Graphene as a spintronic material.
The band structure that I got is not desired as a semimetal(i.e. graphene) and the spin polarization is 

not desired(high %). 


I am appreciate for any suggestion and comments.

"Please tell me where I was wrong or which detail I ignored."
I used the following PWscf code:


1. SCF code:


 &control
  calculation = 'scf'
  restart_mode='from_scratch'
  prefix='graphene'
  tstress=.true.
  tprnfor=.true.
  pseudo_dir = '/home/live/Desktop/pseudo/',
  outdir =
 '/home/live/Desktop/testgraphene/'
  /
  &system
  ibrav=4
  celldm(1)=4.7243
  celldm(3)=3.92
  nat=2
  ntyp=1
  nspin=2
  starting_magnetization(1)=0.6
  ecutwfc=15.0
  ecutrho=350.0
  occupations='smearing'
  smearing='gaussian'
  nbnd = 8
  degauss=0.01
  /
  &electrons
  diagonalization='david'
  electron_maxstep = 100
  mixing_mode='plain'
  mixing_beta=0.1
  conv_thr = 1.0e-8
  /
  ATOMIC_SPECIES
  C 12.011 C.pz-rrkjus.UPF
 
 
  ATOMIC_POSITIONS (angstrom)
  C 0.000000000 0.000000000 0.000000000
  C 1.232850116 0.706423116 0.000000000
  K_POINTS {automatic}
  16 16 1 0 0 0


2. NSCF code:
 &control
  calculation = 'nscf'
 
 restart_mode='from_scratch'
  prefix='graphene'
  tstress=.true.
  tprnfor=.true.
  pseudo_dir = '/home/live/Desktop/pseudo/',
  outdir = '/home/live/Desktop/testgraphene/'
  /
  &system
  ibrav=4
  celldm(1)=4.7243
  celldm(3)=3.92
  nat=2
  ntyp=1
  nspin=2
  starting_magnetization(1)=0.6
  ecutwfc=15.0
  ecutrho=350.0
  occupations='smearing'
  smearing='gaussian'
  nbnd = 8
  degauss=0.01
  /
  &electrons
  diagonalization='david'
  electron_maxstep = 100
  mixing_mode='plain'
  mixing_beta=0.1
  conv_thr = 1.0e-8
  /
  ATOMIC_SPECIES
  C 12.011 C.pz-rrkjus.UPF
 
 
  ATOMIC_POSITIONS (angstrom)
  C 0.000000000 0.000000000 0.000000000
  C 1.232850116 0.706423116
 0.000000000
  K_POINTS {automatic}
  16 16 1 0 0 0




3.pw.x band code:
 &control
  calculation = 'bands'
  restart_mode='from_scratch'
  prefix='graphene'
  tstress=.true.
  tprnfor=.true.
  pseudo_dir = '/home/live/Desktop/pseudo/',
  outdir = '/home/live/Desktop/testgraphene/'
  /
  &system
  ibrav=4
  celldm(1)=4.7243
  celldm(3)=3.92
  nat=2
  ntyp=1
  nspin=2
  starting_magnetization(1)=0.6
  ecutwfc=15.0
  ecutrho=350.0
  occupations='smearing'
  smearing='gaussian'
  nbnd = 8
  degauss=0.01
  /
  &electrons
  diagonalization='david'
  electron_maxstep = 100
  mixing_mode='plain'
  mixing_beta=0.1
  conv_thr = 1.0e-8
  /
  ATOMIC_SPECIES
  C
 12.011 C.pz-rrkjus.UPF
 
 
  ATOMIC_POSITIONS (angstrom)
  C 0.000000000 0.000000000 0.000000000
  C 1.232850116 0.706423116 0.000000000
  K_POINTS {automatic}
  16 16 1 0 0 0


4.band.x code:
&inputpp
   prefix='graphene',
   outdir='/home/live/Desktop/testgraphene/'
   !filband='graphene.bands'
   / 



5.plotband.x code:
bands.out
-10.0 20.0
graphene.xmgr
graphene.ps
1.000
2.0 1.00
EOF 


6. dos.x code:
 &inputpp
  prefix='graphene'
  outdir=/home/live/Desktop/Graphenenbnd8/'
  fildos='graphene.dos',
  Emin=-25.0, Emax=20.0, DeltaE=0.1


Regards-
Rahen Badsha (Raihan)
A post graduate Thesis student
University of Rajshahi, Bangladesh
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