[Pw_forum] R: Re: NOSYM tag + atomization energy

[giacsport at libero.it]

got the point.... thanks, Lorenzo!

By the way, to complete my post, I would like to understand where is the source of my error....I am trying to calculate the atomization energy for C....I always get a value (11.14 eV/atom) well above the experimental one (7.37 eV/atom) and also above other values still calculated at PBE level.
I have tried "adjusting" all the possible parameters (cutoff, vacuum, kpoint sampling), but at the end I am not able to further reduce such value.Has anybody any suggestion for me? The pseudo I use has 2e in 2s and 1.5e in 2p.
Here I attach the two input files for the bulk (8atoms) calculation and for the single atom calculation.
Any hint is very appreciated


BULK_8 ATOM CELL

    calculation = 'vc-relax',
    restart_mode='from_scratch',
    pseudo_dir = './'
    nstep=300
    outdir='./',
    prefix='Carbon',
    tprnfor     = .true.,
    tstress     = .true.,
    wf_collect=.true.,
/
&system
    ibrav=  1, celldm(1) = 6.740274656
    nat=  8, ntyp= 1, nspin=2,
    ecutwfc = 80.,  occupations='smearing',
    degauss=0.01, smearing='gaussian', starting_magnetization(1)=1
/
&electrons
diagonalization='david'
mixing_mode = 'plain'
mixing_beta = 0.7
conv_thr = 1.0d-6
/
&IONS
ion_dynamics='bfgs'
trust_radius_min=1.D-7
/
&CELL
  cell_dynamics='bfgs'
/
ATOMIC_SPECIES
C  12.011    C.pbe-mt_gipaw.UPF
ATOMIC_POSITIONS (crystal)
  C     0.00000   0.00000   0.00000
  C     0.25000   0.25000   0.25000
  C     0.00000   0.50000   0.50000
  C     0.25000   0.75000   0.75000
  C     0.50000   0.00000   0.50000
  C     0.75000   0.25000   0.75000
  C     0.50000   0.50000   0.00000
  C     0.75000   0.75000   0.25000
K_POINTS (automatic)
9 9 9 0 0 0

AND the ATOMIC CASE
&control
    calculation = 'scf',
    restart_mode='from_scratch',
    pseudo_dir = './'
    outdir='./',
    prefix='Carbon.1atom',
    wf_collect=.true.,
/
&system
    ibrav=  1, celldm(1) = 18.,
    nat=  1, ntyp= 1, nspin=2,
    ecutwfc = 80.,  occupations='smearing', nosym=.true.,
    degauss=0.01, smearing='gaussian',
/
&electrons
diagonalization='david'
mixing_mode = 'plain'
mixing_beta = 0.7
conv_thr = 1.0d-6
/
ATOMIC_SPECIES
C  12.011    C.pbe-mt_gipaw.UPF
ATOMIC_POSITIONS (crystal)
  C     0.50000   0.50000   0.50000
K_POINTS (automatic)
1 1 1 0 0 0




Thanks in advance!G




----Messaggio originale----

Da: lorenzo.paulatto at impmc.upmc.fr

Data: 31/05/2012 11.37

A: "giacsport at libero.it"<giacsport at libero.it>, "PWSCF Forum"<pw_forum at pwscf.org>

Ogg: Re: [Pw_forum] NOSYM tag





On Thu, May 31, 2012 at 11:17 AM, giacsport at libero.it <giacsport at libero.it> wrote:

 nosym= 'true',

  Dear Giacomo,nosym=.true. is not the same as nosym='true'

best regards
-- 
Lorenzo Paulatto IdR @ IMPMC/CNRS & Université Paris 6
phone: +33 (0)1 44275 084 / skype: paulatzwww:   http://www-int.impmc.upmc.fr/~paulatto/mail:  23-24/4é16 Boîte courrier 115, 4 place Jussieu 75252 Paris Cédex 05










-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20120531/8a43ff05/attachment.html>