[Pw_forum] same Problem with BFGS

Stefano de Gironcoli degironc at sissa.it
Wed Jul 12 08:24:26 CEST 2006


your scf convergence threshold (10^-4) looks very lousy to me.
In particular it's larger than the required energy convergence 
in the bfgs relaxation (10^-5) !!
Lousy self consitency affects the quality of the computed forces ... 
indeed the "scf correction" is larger that the force itself.

stefano 

Quoting mnunez at ncsu.edu:

> 
> I am getting the same bfgs error posted before:
> -
>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>      from bfgs : error #         1
>      bfgs history already reset at previous step
> 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> 
> stopping ...
> --------------------
> the bfgs algorithm seems to get stucked.
> the total forces along the minimization  before it stops are:
> 
>      Total force =     0.002868     Total SCF correction =     0.034876
>      Total force =     0.042610     Total SCF correction =     0.039637
>      Total force =     0.008934     Total SCF correction =     0.029486
>      Total force =     0.003953     Total SCF correction =     0.016921
>      Total force =     0.012592     Total SCF correction =     0.010567
>      Total force =     0.004110     Total SCF correction =     0.009995
>      Total force =     0.001633     Total SCF correction =     0.012211
>      Total force =     0.001412     Total SCF correction =     0.019146
>      Total force =     0.001607     Total SCF correction =     0.021538
>      Total force =     0.001555     Total SCF correction =     0.012259
>      Total force =     0.001361     Total SCF correction =     0.012868
>      Total force =     0.001432     Total SCF correction =     0.013882
>      Total force =     0.001343     Total SCF correction =     0.011201
>      Total force =     0.001422     Total SCF correction =     0.013635
>      Total force =     0.001369     Total SCF correction =     0.005947
>      Total force =     0.001317     Total SCF correction =     0.011391
>      Total force =     0.001485     Total SCF correction =     0.006279
>      Total force =     0.001351     Total SCF correction =     0.014118
>      Total force =     0.001475     Total SCF correction =     0.011927
> 
> the input file
> &control
>     calculation = "relax",
>     title='scf BaOPtAl big slab 1 001'
>     restart_mode="from_scratch",
>     prefix="BaOPtAlSlabMeth",
>     pseudo_dir ="/spin/home/mnunez/pwcheetah/pseudo/",
>     outdir="/tmp/work/mnunez/BaOPtAlSlabMethod/",
>     forc_conv_thr = 1.0d-4
>     etot_conv_thr = 1.0d-5
>     tstress = .true.,
>     tprnfor = .true.
>  /
>  &system
>     ibrav = 6,
>     celldm(1) =7.297,
>     celldm(3) = 16.9397,
>     nat = 42,
>     ntyp = 4,
>     nbnd=230,
>     ecutwfc =35,
>     ecutrho=245,
>     occupations ='smearing',
>     smearing='gaussian',
>     degauss=0.008
>  / &electrons
>     mixing_mode= 'local-TF'
>     diagonalization= 'cg'
>     mixing_beta = 0.3,
>     mixing_ndim = 11,
>     conv_thr =  1.0d-4
>  /
>  &ions
>     upscale=11
>  /
> ATOMIC_SPECIES
> O 15.9994  O.pz-rrkjus.UPF
> Ba 137.327 Ba.vdb.UPF
> Pt 195.078  Pt.pz-rrkjus.UPF
> Al 26.981538  Al.pz-vbc.UPF
> ATOMIC_POSITIONS
> Pt       0.500000000   0.500000000  -5.843889151
> Pt       0.000000000   0.000000000  -5.841443397
> Pt       0.500000000   0.000000000  -5.341181221
> Pt       0.000000000   0.500000000  -5.341181221
> Pt       0.500000000   0.500000000  -4.831963549
> Pt       0.000000000   0.000000000  -4.829809502
> Pt       0.500000000   0.000000000  -4.316032074
> Pt       0.000000000   0.500000000  -4.316032074
> Pt       0.500000000   0.500000000  -3.800183390
> Pt       0.000000000   0.000000000  -3.799129595
> Pt       0.500000000   0.000000000  -3.250938002
> Pt       0.000000000   0.500000000  -3.250938002
> Al       0.500000000   0.500000000  -2.892741738
> Al       0.000000000   0.000000000  -2.774954863
> Ba       0.500000000   0.500000000  -2.105588663
> O        0.000000000   0.000000000  -2.318966082
> Ba       0.000000000   0.000000000  -1.375247423
> O        0.500000000   0.500000000  -1.434073949
> Ba       0.500000000   0.500000000  -0.681716547
> O        0.000000000   0.000000000  -0.728523986
> Ba       0.000000000   0.000000000   0.025502608
> O        0.500000000   0.500000000  -0.009862356
> Ba       0.500000000   0.500000000   0.726855678
> O        0.000000000   0.000000000   0.705024595
> Ba       0.000000000   0.000000000   1.435097711
> O        0.500000000   0.500000000   1.393104543
> Ba       0.500000000   0.500000000   2.115982686
> O        0.000000000   0.000000000   2.118086625
> Pt       0.500000000   0.500000000   2.836917653
> Pt       0.000000000   0.000000000   2.696183926
> Pt       0.500000000   0.000000000   3.298956976
> Pt       0.000000000   0.500000000   3.298956976
> Pt       0.500000000   0.500000000   3.810364151
> Pt       0.000000000   0.000000000   3.819965483
> Pt       0.500000000   0.000000000   4.332138351
> Pt       0.000000000   0.500000000   4.332138351
> Pt       0.500000000   0.500000000   4.850766432
> Pt       0.000000000   0.000000000   4.844433414
> Pt       0.500000000   0.000000000   5.360902198
> Pt       0.000000000   0.500000000   5.360902198
> Pt       0.500000000   0.500000000   5.860968442
> Pt       0.000000000   0.000000000   5.865188929
> K_POINTS {automatic}
>  6 6 1 1 1 0
> 
> 
> the pseudopotentials used are the ones in
> 
> http://www.pwscf.org/pseudo.htm
> 
> 
> 
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
> 




----------------------------------------------------------------
  SISSA Webmail https://webmail.sissa.it/
  Powered by Horde http://www.horde.org/




More information about the users mailing list