[Pw_forum] Problens with etot_vs_alat of gold

[Aline Bidoul]

Hi everyone!
I'm new in Quantum-Espresso and i having problems to minimize que lattice
parameter of gold
The minimum energy is with 7.0A and in literature we find 4.07 A and in
other programs i find 4.2
I'm using this code to calculate the curve

#!/bin/sh
####################################################################
#
# define the following variables according to your needs
#
#espresso_dir=top_directory_of_espresso_package
outdir=/home'
pseudo_dir=/home/pseudo'
####################################################################

rm -f au.scf.out au.etot_vs_alat
touch au.etot_vs_alat

for alat in  4.05 4.06 4.07 4.08 4.09 4.1 4.2 5.0 6.0 7.0 8.0 9.0 ; do

# self-consistent calculation
cat > au.scf.in << EOF
&control
    calculation = 'scf'
    prefix='gold',
    pseudo_dir = pseudo_dir,
    outdir= outdir,
 /
 &system
    ibrav=  2, a=$alat , nat=  4, ntyp= 1,
    ecutwfc = 40.0, ecutrho = 480.0,
    occupations='smearing', smearing = 'mv', degauss = 0.002
 /
 &electrons
    mixing_mode = 'local-TF'
    mixing_beta = 0.7
    conv_thr = 1.0d-6
 /
ATOMIC_SPECIES
 Au  196.96654  Au.bp-van_ak.UPF
ATOMIC_POSITIONS (crystal)
 Au 0.00 0.00 0.00
 Au 0.5  0.5  0.0
 Au 0.5  0.0  0.5
 Au 0.0  0.5  0.5
K_POINTS automatic
   8 8 8 1 1 1

EOF

pw.x < au.scf.in > au.scf.out

grep -e 'lattice parameter' -e ! au.scf.out | \
      awk '/lattice/{a=$(NF-1)}/!/{print a, $(NF-1)}' >> au.etot_vs_alat

done

I find this in a tutorial of Professor Narasimhan. 7.0 A i think is large
for gold, so i try to find for Silver and the alat was almost the same. I
tested all the PP for gold that i find in the QE page, and has the same
result with different energies values. If some one could help i will be
grateful.


-- 
Aline A. Bidoul
Engenheira Física
Mestranda em Engenharia Biomédica
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20140505/0cb102ca/attachment.html>