Dear Aline A Bidoul,
You might want to check how many atoms are in the fcc unit cell if you
indeed use the FCC as the basis (ibrav = 2).
Greetings,
apsi
-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-
Ari Paavo Seitsonen / Ari.P.Seitsonen at iki.fi / http://www.iki.fi/~apsi/
Institut f?r Chemie der Universit?t Z?rich, CH-8057 Z?rich
Tel: +41 44 63 54 497 / Mobile: +41 79 71 90 935
On Mon, 5 May 2014, Aline Bidoul wrote:
> 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. BidoulEngenheira F?sica
> Mestranda em Engenharia Biom?dica
>
>
