Hello,
I'm performing some first test-calculations with pwscf, where I try to
get the binding energy of bulk silicon. The problem is, that the
resulting energy, which should be the difference of the total
energy of silicon crystal structure and the a free atom, is about 3eV
too low. I used different pseudopotentials, different
lattice-parameters and I also tested the convergencies (with k and
the energy-cut-off) which worked, but I don't have a clue what a made
wrong.
Here are my Input files:
---
&control
prefix='silicon',
pseudo_dir='/home/joerg/espresso-4.3.1/pseudo'
outdir = '/home/joerg/scratch',
/
&system
ibrav= 2, celldm(1) =10.263142, nat= 2, ntyp= 1,
ecutwfc = 30.0,
/
&electrons
/
ATOMIC_SPECIES
Si 28.086 Si.pbe-n-van.UPF
ATOMIC_POSITIONS
Si 0.00 0.00 0.00
Si 0.25 0.25 0.25
K_POINTS automatic
9 9 9 1 1 1
---
and for the free atom:
---
&control
prefix='silicon',
pseudo_dir='/home/joerg/espresso-4.3.1/pseudo'
outdir = '/home/joerg/scratch',
/
&system
ibrav= 0, celldm(1) =50.2, nat= 1, ntyp= 1,
ecutwfc = 80.0,occupations='fixed',starting_magnetization(1)=10,
/
&electrons
/
ATOMIC_SPECIES
Si 28.086 Si.pbe-n-van.UPF
ATOMIC_POSITIONS
Si 0.50 0.50 0.50
K_POINTS gamma
CELL_PARAMETERS {cubic}
1.00 0.00 0.00
0.00 1.00 0.00
0.00 0.00 1.00
---
It would be nice if someone could help me.
Thx & regards,
J?rg Buchwald
Leibniz-Institut fuer Oberflaechenmodifizierung e.V.
Permoserstrasse 15
04318 Leipzig
GERMANY
