[Pw_forum] convergence issue in vc-relax: final scf step

Mohammadreza Karamad karamadr at gmail.com
Thu Apr 6 19:52:28 CEST 2017


Dear Users,


I am running some vc-relax pw.x calculations. However, I have not been able
to converge the calculations so far. It seems that, the final
self-consistent calculation after the relaxation is not converged. Of
course, I can extract cell parameters at that point; However, it would be
the best if the final scf calculations are converged. It seems that the
code crashes at the point of doing this self-consistent calculation because
often the unit cell has changed too much. I have played a boit with degauss
and tried 0.005 and 0.007 and 0.1 values, however in all cases the final
scf calculations failed, i.e., did not converge. Below I am attaching both
input and output files. Any feedback will be appreciates.

Regards,

Reza


Input:

&CONTROL
! .control.settings.
calculation               = 'vc-relax',
prefix                    = 'sys',
pseudo_dir                = '/project/projectdirs/esp-psp/v2',

! .control.io.
disk_io                   = 'high',
wf_collect                = .false.,
outdir                    = './tmp/',

! .control.ion_relax.
etot_conv_thr             = 1.0D-4,
forc_conv_thr             = 1.0D-3,
nstep                     = 400,
tprnfor                   = .true.,
tstress                   = .true.,
/

&SYSTEM
! .system.structure.
nosym                     = .true.,
ibrav                     = 0,
nat                       = 24,
ntyp                      = 3,

! .system.ecut.
ecutwfc                   = 45,
ecutrho                   = 450,

! .system.occupations.
degauss                   = 0.005,
smearing                  = 'mv',
input_dft                 = 'PBE',
occupations               = 'smearing',

! .system.UH.
/

&ELECTRONS
! .electrons.
startingwfc               = 'random',
diagonalization           = 'cg',
mixing_mode               = 'local-TF',
electron_maxstep          = 800,
mixing_beta               = 0.7D0,
conv_thr                  = 1e-06,
/

&IONS
! .ions.
pot_extrapolation         = 'none',
wfc_extrapolation         = 'none',
ion_dynamics              = 'bfgs',
/

&CELL
! .cell.
cell_dynamics             = 'bfgs',
cell_factor               = 5,
/

ATOMIC_SPECIES
   Na   0.0000 Na.UPF
    O   0.0000 O.UPF
   Ti   0.0000 Ti.UPF

ATOMIC_POSITIONS  angstrom
 Na     8.57186687132953     3.88720697276125    10.63939984990235   1
1   1
 Na     4.83885672340138     3.89066227771078     5.32747072765901   1
1   1
 Na     1.25674393339731     0.72654822099638     0.00553536631243   1
1   1
 Na     4.98975408132547     0.72309291604685     5.31746448855577   1
1   1
 Na     2.24899540236342     2.30687759687882     5.32246760810739   1
1   1
 Na     3.99780607418619     2.30973803360433     0.00000000000000   1
1   1
 Na     3.12322191350827     3.84026580758467     2.65910481701045   1
1   1
 Na     6.70538889121858     0.77348938617296     7.98583039920433   1
1   1
  O     8.36497999311758     3.66351735301855     6.88450540173475   1
1   1
  O     2.11551764077806     2.09385370364779     1.57736650033871   1
1   1
  O     5.04718107061696     3.66219368980115     9.08960373177364   1
1   1
  O     1.46363081160926     0.95023784073908     3.76042981448003   1
1   1
  O     5.13219847814359     3.83438458736690     1.56863765346141   1
1   1
  O     4.13190146700371     2.09287331239471     3.74542045582517   1
1   1
  O     7.71309316394878     2.51990149010984     9.06756871587608   1
1   1
  O     5.69670933772314     2.52088188136292     6.89951476038961   1
1   1
  O     3.38297493594591     0.77998893390266     6.89429874213367   1
1   1
  O     6.44563586878094     3.83376625985497     3.75063647408112   1
1   1
  O     4.69641232658325     0.77937060639073     9.07629756275337   1
1   1
  O     4.78142973410988     0.95156150395648     1.55533148444114   1
1   1
 Ti     3.12365348909562     0.76337161233394     2.65867901960180   1
1   1
 Ti     4.04007389946279     2.29620888405152     7.98284981734379   1
1   1
 Ti     5.78853690526406     2.31754630970611     2.66208539887099   1
1   1
 Ti     6.70495731563122     3.85038358142369     7.98625619661298   1
1   1
CELL_PARAMETERS  angstrom
    5.33062000000000     0.00000000000000     0.00000000000000
    2.66499214837238     4.61947606720866     0.00000000000000
    1.83299865635447    -0.00572087345103    10.64493521621478

K_POINTS automatic
   4    4    2   0   0   0

     total energy              =   -1298.51296289 Ry
     total energy              =   -1298.45312293 Ry
     total energy              =   -1298.38950663 Ry
     total energy              =   -1298.48142592 Ry
     total energy              =   -1298.47615128 Ry
     total energy              =   -1298.44573413 Ry
     total energy              =   -1298.36097598 Ry
     total energy              =   -1298.45981099 Ry
     total energy              =   -1298.48328543 Ry
     total energy              =   -1298.43916771 Ry
     total energy              =   -1298.37607574 Ry
     total energy              =   -1298.43025640 Ry
     total energy              =   -1298.47173883 Ry
     total energy              =   -1298.42092069 Ry
     total energy              =   -1298.35524073 Ry
     total energy              =   -1298.41115739 Ry
     total energy              =   -1298.44980664 Ry
     total energy              =   -1298.41445717 Ry
     total energy              =   -1298.38515141 Ry
     total energy              =   -1298.42892457 Ry
     total energy              =   -1298.42791076 Ry
     total energy              =   -1298.42632216 Ry
     total energy              =   -1298.37976733 Ry
     total energy              =   -1298.40719745 Ry
     total energy              =   -1298.42183088 Ry
     total energy              =   -1298.44336709 Ry
     total energy              =   -1298.40580765 Ry
     total energy              =   -1298.44706216 Ry
     total energy              =   -1298.43744427 Ry
     total energy              =   -1298.41177837 Ry
     total energy              =   -1298.40567244 Ry
     total energy              =   -1298.42082515 Ry
     total energy              =   -1298.47392836 Ry
     total energy              =   -1298.40719551 Ry
     total energy              =   -1298.39589116 Ry
     total energy              =   -1298.39223577 Ry
     total energy              =   -1298.46155905 Ry
     total energy              =   -1298.38847359 Ry
     total energy              =   -1298.40618588 Ry
     total energy              =   -1298.34448292 Ry
     total energy              =   -1298.42666404 Ry
     total energy              =   -1298.41083743 Ry
     total energy              =   -1298.40323410 Ry
     total energy              =   -1298.40214736 Ry
     total energy              =   -1298.45137067 Ry
     total energy              =   -1298.38509052 Ry
     total energy              =   -1298.40240682 Ry
     total energy              =   -1298.35828629 Ry
     total energy              =   -1298.41203913 Ry
     total energy              =   -1298.36659649 Ry
     total energy              =   -1298.37564420 Ry

And, here is the tail of the output file:
     iteration #799     ecut=    45.00 Ry     beta=0.70
     CG style diagonalization
     ethr =  8.45E-07,  avg # of iterations =  4.4

     total cpu time spent up to now is    36238.5 secs

     total energy              =   -1298.36659649 Ry
     Harris-Foulkes estimate   =   -1298.36657570 Ry
     estimated scf accuracy    <       0.00493470 Ry

     iteration #800     ecut=    45.00 Ry     beta=0.70
     CG style diagonalization
     ethr =  8.45E-07,  avg # of iterations =  4.5

     total cpu time spent up to now is    36275.4 secs

     total energy              =   -1298.37564420 Ry
     Harris-Foulkes estimate   =   -1298.37566856 Ry
     estimated scf accuracy    <       0.00758950 Ry

     End of self-consistent calculation

     convergence NOT achieved after 800 iterations: stopping
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20170406/10516a90/attachment.html>


More information about the users mailing list