[Pw_forum] Two vacuum energies with dipole correction

[N H Joshi]

Hello,
I need to calculate the work function of Ni(111) slab.

So I am doing the calculations by including the dipole correction so as to
identify the vacuum level .
Please find the input file at the end.

But with the correction I see a step in the vacuum region in the
electrostatic potential plot of around 0.2 eV
and I am unable to decide which of the two vacuum energies should I use to
calculate the work function and why.


&control
    calculation = 'relax'
    prefix='Ni-dipcorr',
    tprnfor = .true.
    pseudo_dir = '.',
    outdir='.'
    wf_collect=.true.
    tefield=.true.
    dipfield=.true.

  /
 &system
    ibrav= 0,
    nat= 6, ntyp= 1,
    ecutwfc =35
    ecutrho =360,
    occupations='smearing',
    smearing='mv',
    degauss=0.01,
    nspin=2
    starting_magnetization(1)=1.0
    emaxpos=0.6
    eopreg=0.05
    eamp=0
    edir=3
/
&electrons
   conv_thr =  1.0d-8
   mixing_beta = 0.2
   mixing_mode='local-TF'

/
&IONS
/
ATOMIC_SPECIES
   Ni  58.6931 Ni.pbe-nd-rrkjus.UPF
ATOMIC_POSITIONS (angstrom)
Ni       0.000000000   0.000000000   0.000000000    0   0   0
Ni       2.779543930  -0.744776550   2.034767380    0   0   0
Ni       1.389771960  -0.372388280   4.069534750    0   0   0
Ni       0.000000000   0.000000000   6.100912698
Ni       2.779543930  -0.744776550   8.127474042
Ni       1.389771889  -0.372388192  10.129931733

K_POINTS {automatic}
   12 12 1 1 1 1
CELL_PARAMETERS {hexagonal}
    3.330000000   -3.330000000  0.00000000
    4.54886459   1.218864589  0.00000000
    0.0000000000    0.0000000000   50.0

Regards,
Niharika Joshi
Project student,
Department of Physics,
IISER, Pune,
India.
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