Dear Aline, if you are using FCC structure (ibrav=2), you must to use only "one" atom, at the position 0.00 0.00 0.00, and change "nat=1" Please read about that in any solid state book.
Best PhD. Arles V. Gil Rebaza Instituto de F?sica de La Plata La Plata - Argentine 2014-05-05 18:19 GMT-03:00 Ari P Seitsonen <Ari.P.Seitsonen at iki.fi>: > > 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 >> >> > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum > -- ###---------> Arles V. <---------### -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20140505/2943b238/attachment.html
