[Pw_forum] Bonding Energy

[Michal Lemieszewski]

Dear PWscf users,

I have tried to calculate bonding energy between Ni-Ni and Pd-Pd. Then I
would try to calculate energy of a layer.
The file to calculate Ni-Ni I have used from example1 file and modify it to
my case, but I got "strange" results (to both calculations).
Therefore I have two questions involving my calculations:
1. Can PWscf make so type of calculations? If so can You tell my what am I
doing wrong?
2. How can I calculate celldm(1) in general (for example for Pd), I know the
cell parameters but I
don't know how to translate them to celldm(1).
I think it should be exact value (or could it be estimated?).

Please forgive me if those are trivial questions, but I am new in this field
and I am learning ( I am undergraduate student).
I also want to ask if You could recommend  me some articles or ("good") web
pages about Ni, Pd (e.g. experimental values) k-points and
things which You think I should read to understand more about program and my
problem (catalysis).

I enclose example files for Ni.

Thanks,
                Michal

#
# self-consistent calculation
#
cat > ni.scf0.in << EOF
 &control
    calculation='scf'
    restart_mode='from_scratch',
    pseudo_dir = '$PSEUDO_DIR/',
    outdir='$TMP_DIR/'
    prefix='ni'
    tprnfor = .true.,
    tstress = .true.
 /
 &system
    ibrav=2, celldm(1) =6.48, nat=1, ntyp=1,
    nspin = 2,  starting_magnetization(1)=0.7,
    ecutwfc = 24.0, ecutrho = 288.0,
    occupations='smearing', smearing='methfessel-paxton', degauss=0.02
 /
 &electrons
    conv_thr = 1.0e-8
    mixing_beta = 0.7
 /
ATOMIC_SPECIES
 Ni 58.69 NiUS.RRKJ3.UPF
ATOMIC_POSITIONS{angstrom}
 Ni 0.0 0.0 0.0
K_POINTS{gamma}
EOF

#
# self-consistent calculation
#
for i in `seq 1.0 0.1 5.0`;do
cat > ni.scf$i.in << EOF
 &control
    calculation='scf'
    restart_mode='from_scratch',
    pseudo_dir = '$PSEUDO_DIR/',
    outdir='$TMP_DIR/'
    prefix='ni'
    tprnfor = .true.,
    tstress = .true.
 /
 &system
    ibrav=2, celldm(1) =6.48, nat=2, ntyp=1,
    nspin = 2,  starting_magnetization(1)=0.7,
    ecutwfc = 24.0, ecutrho = 288.0,
    occupations='smearing', smearing='methfessel-paxton', degauss=0.02
 /
 &electrons
    conv_thr = 1.0e-8
    mixing_beta = 0.7
 /
ATOMIC_SPECIES
 Ni 58.69 NiUS.RRKJ3.UPF
ATOMIC_POSITIONS{angstrom}
 Ni 0.0 0.0 0.0
 Ni $i  0.0 0.0
K_POINTS{gamma}
EOF