[CPMD-list] Convergence problem with USPP

[Linas Vilciauskas]

Thanks for the prompt reply and sorry for not providing enough
details... I certainly followed the rules in the manual for selecting
the box size for an isolated system calculation and at lest for the
norm-conserving PPs the box size (in this case 8.0 A) was never a
problem (neither with LDA nor GGA nor Hybrid XC functionals). Here is
my full input:

Sample input:

&INFO
&END

&CPMD
  OPTIMIZE GEOMETRY XYZ
  STRUCTURE BONDS ANGLES DIHEDRALS
  PCG MINIMIZE
  ODIIS NO_RESET=30
   10
  MAXSTEP
   1000
&END

&DFT
  FUNCTIONAL BLYP
  GC-CUTOFF
   5.D-6
&END

&SYSTEM
  SYMMETRY
   0
  ISOLATED MOLECULE
  ANGSTROM
  CELL
   8.0 1.0 1.0 0.0 0.0 0.0
  CUTOFF
   25.0
  DUAL
   5.0
&END

&ATOMS
*P_VDB_BLYP.psp FORMATTED
  LMAX=P
   2
  -2.394917   -0.130691   -0.442475
  -0.323809    2.480816    1.970286

*O_VDB_BLYP.psp FORMATTED
  LMAX=P
   8
  -3.800575   -0.695687   -0.967861
  -2.220024   -0.256766    1.033758
  -1.358141   -0.988753   -1.307625
  -2.282227    1.318659   -1.030921
  -1.161599    1.418333    2.763236
  -0.755639    2.744989    0.566853
  -0.317814    3.792773    2.892051
   1.188019    1.977302    2.114271

*H_VDB_BLYP.psp FORMATTED
  LMAX=S
   6
  -4.543162   -0.409366   -0.423954
  -1.227273   -1.878121   -0.959249
  -1.684876    1.918836   -0.497156
  -1.571156    0.717894    2.177084
  -1.109816    4.330419    2.778487
   1.800148    2.469017    1.554849
&END


On Tue, Apr 1, 2008 at 11:58 AM, Axel Kohlmeyer
<akohlmey at cmm.chem.upenn.edu> wrote:
> On Tue, 1 Apr 2008, Linas Vilciauskas wrote:
>
>  LV> Dear CPMD community,
>
>  dear linas,
>
>  [...]
>
>  LV> problem with USPPs for certain atoms/combinations? Does anybody have
>  LV> some ideas?
>
>  i suspect your box is to small, but since you were omitting
>  the most important part of the input to identify this,
>  the coordinates, nobody can tell for sure. please have a look
>  at the comments that the manual has about choosing the box
>  for isolated system calculations.
>
>  cheers,
>    axel.
>  LV>
>  LV> System info:
>  LV> CPMD 3.11.1
>  LV> OS: IBM AIX 5.2 L
>  LV> FCC: IBM XL 8.1.1 (OpenMP only)
>  LV>
>  LV> Sample input:
>  LV> &INFO
>  LV> &END
>  LV>
>  LV> &CPMD
>  LV>  OPTIMIZE GEOMETRY XYZ
>  LV>  STRUCTURE BONDS ANGLES DIHEDRALS
>  LV>  PCG MINIMIZE
>  LV>  ODIIS NO_RESET=30
>  LV>   10
>  LV>  MAXSTEP
>  LV>   1000
>  LV> &END
>  LV>
>  LV> &DFT
>  LV>  FUNCTIONAL BLYP
>  LV>  GC-CUTOFF
>  LV>   5.D-6
>  LV> &END
>  LV>
>  LV> &SYSTEM
>  LV>  SYMMETRY
>  LV>   0
>  LV>  ISOLATED MOLECULE
>  LV>  ANGSTROM
>  LV>  CELL
>  LV>   8.0 1.0 1.0 0.0 0.0 0.0
>  LV>  CUTOFF
>  LV>   25.0
>  LV>  DUAL
>  LV>   5.0
>  LV> &END
>  LV>
>  LV> &ATOMS
>  LV> *P_VDB_BLYP.psp FORMATTED
>  LV> ...............
>  LV> *O_VDB_BLYP.psp FORMATTED
>  LV> ...............
>  LV> *H_VDB_BLYP.psp FORMATTED
>  LV> ..............
>  LV> &END
>  LV>
>  LV>
>  LV>  --
>  LV> Linas Vilciauskas
>  LV> Max-Planck-Institut für Festkörperforschung
>  LV> Heisenbergstraße 1
>  LV> D-70569 Stuttgart, Germany
>  LV> _______________________________________________
>  LV> CPMD-list mailing list
>  LV> CPMD-list at cpmd.org
>  LV> http://cpmd.org/mailman/listinfo/cpmd-list
>  LV>
>
>  --
>  =======================================================================
>  Axel Kohlmeyer   akohlmey at cmm.chem.upenn.edu   http://www.cmm.upenn.edu
>    Center for Molecular Modeling   --   University of Pennsylvania
>  Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323
>  tel: 1-215-898-1582,  fax: 1-215-573-6233,  office-tel: 1-215-898-5425
>  =======================================================================
>  If you make something idiot-proof, the universe creates a better idiot.