NaNs in wave function cube files

Matthias Krack matthia... at psi.ch
Fri Nov 20 09:04:40 CET 2009


Hi Claudio,

the generation of the wavefunction cube files involves a collocation
of the Gaussian basis functions on the real-space grid and CP2K
employs a multi-grid scheme for efficiency reasons, ie. large Gaussian
exponents are collocated on denser grids and small ones on coarser
grids. The assembly of the all grids is then performed in Fourier
space and thus a FFT is performed for each grid level and the
combination of all grid levels is back-transformed to real space. In
the case of GAPW, usually large exponents are employed and the FFT
steps might introduce numerical instabilities especially if the grid
is not sufficiently large (dense). If I am not mistaken and this is
the source of the NaNs in your wavefunction cube files then I can
suggest the following solutions: (1) try to use a very large cutoff
(e.g. 600 Ry or more) to reduce the numerical instabilities, (2) just
use a single (large) grid to avoid the FFT steps. The latter solution
requires a code change, since the usage of multi-grids is the default
and even for a single grid the FFT step is performed.

Matthias

On Nov 19, 1:36 pm, Claudio <marg... at gmail.com> wrote:
> BTW, I noticed there are no NaNs with 3-21g* instead.
>
> Any ideas?
>
> Thanks!
>
> Claudio
>
> On Nov 18, 3:56 am, Claudio <marg... at gmail.com> wrote:
>
> > Dear all, thanks for your help trying to run periodic b3lyp.
>
> > Though my run appears to converge, it writes seemingly correct density
> > and spin cubes, wave function cubes are filled with NaNs after the
> > geometry block. A typical input file that will generate this errors
> > follows. The version of CP2K is yesterday's  CVS. An older version
> > from a month ago also does this.
>
> > &FORCE_EVAL
> >   METHOD Quickstep
> >   &DFT
> >     LSD
> >     CHARGE -1
> >     MULTIPLICITY 2
> >     BASIS_SET_FILE_NAME /home/claudiom/src/cp2k/tests/QS/
> > EMSL_BASIS_SETS
> >     POTENTIAL_FILE_NAME /home/claudiom/src/cp2k/tests/QS/POTENTIAL
> >     &MGRID
> > !      CUTOFF 200
> > !      REL_CUTOFF 50
> >     &END MGRID
> >     &QS
> >       METHOD GAPW
> >       EPS_PGF_ORB 1.0E-16
> >     &END QS
> >     &PRINT
> >         &MO_CUBES
> >           NHOMO 5
> >           NLUMO 5
> >         &END
> >         &E_DENSITY_CUBE
> >         &END
> >    &END PRINT
> >     &SCF
> >       EPS_SCF 1.0E-4
> >       SCF_GUESS RESTART
> >       MAX_SCF 60
> >           &OT
> >           &END OT
> >           &OUTER_SCF
> >               MAX_SCF 1
> >           &END OUTER_SCF
> >     &END SCF
> > #These are the coefficients used for B3LYP using VWN3, this is the
> > default Gaussian definition, but not recommended
> >     &XC
> >       &XC_FUNCTIONAL
> >        &LYP
> >          SCALE_C 0.81
> >        &END LYP
> >        &BECKE88
> >          SCALE_X 0.72
> >        &END BECKE88
> >        &VWN
> >          FUNCTIONAL_TYPE VWN3
> >          SCALE_C 0.19
> >        &END VWN
> >        &XALPHA
> >          SCALE_X 0.08
> >        &END XALPHA
> >       &END XC_FUNCTIONAL
> >       &HF
> >         &SCREENING
> >           EPS_SCHWARZ 1.0E-10
> >           SCREEN_ON_INITIAL_P FALSE
> >         &END SCREENING
> >         &INTERACTION_POTENTIAL
> >           POTENTIAL_TYPE TRUNCATED
> >           CUTOFF_RADIUS 15.000
> >           T_C_G_DATA /home/claudiom/src/cp2k/tests/QS/t_c_g.dat
> >         &END INTERACTION_POTENTIAL
> >         &MEMORY
> >           MAX_MEMORY 768
> >           EPS_STORAGE_SCALING 1.0E-1
> >         &END MEMORY
> >         FRACTION 0.20
> >       &END HF
> >     &END XC
> >   &END DFT
> >   &SUBSYS
> >     &CELL
> >       ABC 31.000 31.000 31.000
> >       PERIODIC XYZ
> >     &END CELL
> >     &COORD
> >  C         2.724300       -0.210525        1.679657
> >  N         3.378813        0.142337        0.367635
> >  C         2.628981       -0.547029       -0.747413
> >  C         3.308675        1.641065        0.186405
> >  C         4.824483       -0.335730        0.427386
> >  C         5.707747        0.076171       -0.750114
> >  C         7.039619       -0.686925       -0.723046
> >  N        -2.115674        0.098149        0.566927
> >  S        -1.065879        1.188462       -0.004405
> >  O        -0.096986        1.688012        0.992480
> >  O        -0.543935        0.938005       -1.360293
> >  S        -1.679594       -1.425080        0.861473
> >  O        -0.223810       -1.659926        0.878041
> >  O        -2.517197       -1.975152        1.928867
> >  C        -2.318886        2.581971       -0.206516
> >  C        -2.273741       -2.356150       -0.672280
> >  F        -3.277763        2.255810       -1.085288
> >  F        -1.666785        3.662915       -0.676494
> >  F        -2.893950        2.911808        0.957784
> >  F        -2.046785       -3.675730       -0.512894
> >  F        -1.628775       -1.949980       -1.775445
> >  F        -3.592764       -2.180301       -0.862609
> >  H         3.269846        0.294602        2.481570
> >  H         2.778648       -1.293048        1.815246
> >  H         1.683606        0.110359        1.652541
> >  H         1.595470       -0.201469       -0.749459
> >  H         2.666731       -1.624615       -0.575470
> >  H         3.104631       -0.308923       -1.698754
> >  H         3.927011        2.115369        0.954315
> >  H         2.265541        1.948040        0.284571
> >  H         3.693613        1.904240       -0.800118
> >  H         4.768472       -1.425574        0.513280
> >  H         5.238050        0.053710        1.365517
> >  H         5.910151        1.153814       -0.709845
> >  H         5.210145       -0.119752       -1.706544
> >  H         7.575766       -0.520996        0.219045
> >  H         6.886641       -1.766428       -0.838317
> >  H         7.681022       -0.342145       -1.545307
> > &END COORD
> >     &KIND H
> >       BASIS_SET 6-31Gxx
> >       POTENTIAL ALL
> >     &END KIND
> >     &KIND F
> >       BASIS_SET 6-31Gxx
> >       POTENTIAL ALL
> >     &END KIND
> >     &KIND C
> >       BASIS_SET 6-31Gxx
> >       POTENTIAL ALL
> >     &END KIND
> >     &KIND N
> >       BASIS_SET 6-31Gxx
> >       POTENTIAL ALL
> >     &END KIND
> >     &KIND S
> >       BASIS_SET 6-31Gxx
> >       POTENTIAL ALL
> >     &END KIND
> >     &KIND O
> >       BASIS_SET 6-31Gxx
> >       POTENTIAL ALL
> >     &END KIND
> >   &END SUBSYS
> > &END FORCE_EVAL
> > &GLOBAL
> >   PROJECT HF-ion-pair
> >   PRINT_LEVEL MEDIUM
> >   RUN_TYPE ENERGY
> >   ECHO_INPUT
> > &END GLOBAL
>
>



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