Different version, different result?

Andy Van Yperen-De Deyne andy.vanyp... at ugent.be
Fri Oct 30 13:07:34 CET 2009


Hello,

When I wanted to reproduce some g-tensors of an older version of CP2K,
using the new version of CP2K, I noticed a (rather large) difference
(especially for the GAPW).
Then I used a compilation of an older version of CP2K (2008
something), I noticed that even the total energy of the single point
calculation is different in both versions (lets call them for now 2008
and 2009).

ENERGY_2008  -18.770810474185076
ENERGY_2009  -18.785104003918622

So it seems logical that the property calculation is different. I used
the exact same inputfile for both versions. I want to mention that I
had the idea that the 2009 version was slower then the 2008
version...

I am trying to sort things out and find the essential difference
between the two inputfiles.
I noticed in the 2008 outputfile this line
CELL| Grid size for subcell
generation                                    2.000
which is not present for the 2009 output. But looking into the manual,
it seems that the default value for this property in the 2009
inputfile is also 2.000.

However, when I look at the "PW_GRID:"-section in the output, I see
that this grid of the 2009 version is different from the 2008 version.
To give you one example

2009
PW_GRID: Information for grid
number                                          1
 PW_GRID: Cutoff
[a.u.]                                                    300.0
 PW_GRID: spherical
cutoff:                                                   NO
 PW_GRID:   Bounds   1            -75      74
Points:         150
 PW_GRID:   Bounds   2            -75      74
Points:         150
 PW_GRID:   Bounds   3            -75      74
Points:         150
 PW_GRID: Volume element (a.u.^3)  0.2000E-02     Volume (a.u.^3)
6748.3346
 PW_GRID: Grid span
FULLSPACE

2008
 PW_GRID: Information for grid
number                                          1
 PW_GRID: Cutoff
[a.u.]                                                    300.0
 PW_GRID: spherical
cutoff:                                                   NO
 PW_GRID:   Bounds   1            -40      39
Points:          80
 PW_GRID:   Bounds   2            -40      39
Points:          80
 PW_GRID:   Bounds   3            -40      39
Points:          80
 PW_GRID: Volume element (a.u.^3)  0.1953E-02     Volume (a.u.^3)
1000.0000
 PW_GRID: Grid span
FULLSPACE

(for all the other grids there is also a similar difference...)

I guess some default value has changed and I wonder if it is possible
to change it back to the 2008 values or vice versa? I have not found a
solution in the manual (I apologize if it is just a trivial keyword
that I did not found).

Or is there another reason for the big difference in energy between
the two versions of CP2K?

Thank you for your attention,

Andy Van Yperen-De Deyne
Center for Molecular Modeling
Ghent University
Technologiepark Zwijnaarde 903
Andy.VanYp... at UGent.be


INPUTFILE


! G tensor calculation just for a testrun

&GLOBAL
    PRINT_LEVEL MEDIUM
    PROJECT_NAME regtest
    RUN_TYPE    LINEAR_RESPONSE !ENERGY
    WALLTIME    -1.00
    PREFERRED_FFT_LIBRARY FFTSG
&END GLOBAL

&FORCE_EVAL

    &SUBSYS

        &CELL
            ABC         10.0 10.0 10.0
            PERIODIC    NONE
        &END CELL

        &TOPOLOGY
            CONNECTIVITY OFF
            COORD_FILE_NAME opt.xyz
            COORD_FILE_FORMAT XYZ
        &END TOPOLOGY

        &KIND O
            BASIS_SET TZVP-MOLOPT-GTH
            POTENTIAL GTH-PBE-q6
        &END KIND

        &KIND B
            BASIS_SET DZVP-MOLOPT-SR-GTH
            POTENTIAL GTH-PBE-q3
        &END KIND

        &KIND C
            BASIS_SET TZVP-MOLOPT-GTH
            POTENTIAL    GTH-PBE-q4
        &END KIND

        &KIND H
            BASIS_SET TZVP-MOLOPT-GTH
            POTENTIAL GTH-PBE-q1
        &END KIND

        &KIND N
            BASIS_SET TZVP-MOLOPT-GTH
            POTENTIAL GTH-PBE-q5
        &END KIND

        &KIND F
            BASIS_SET TZVP-MOLOPT-GTH
            POTENTIAL GTH-PBE-q7
        &END KIND

    &END SUBSYS

    &DFT
        LSD
        CHARGE  0
        MULTIPLICITY 2
        BASIS_SET_FILE_NAME BASIS_MOLOPT
        POTENTIAL_FILE_NAME GTH_POTENTIALS

        &MGRID
            CUTOFF 300
            NGRIDS 5
        &END MGRID

        &QS
            METHOD GAPW
            EXTRAPOLATION PS
            EXTRAPOLATION_ORDER 2
        &END QS

        &XC
            &XC_FUNCTIONAL  PBE
            &END XC_FUNCTIONAL
        &END XC

        &POISSON
            PERIODIC   NONE
            POISSON_SOLVER MT
        &END POISSON

        &SCF
            EPS_SCF 1.0E-5
            MAX_SCF 50
            SCF_GUESS ATOMIC
            &OUTER_SCF
                EPS_SCF 1.0E-5
                MAX_SCF 10
            &END OUTER_SCF
            &OT
                MINIMIZER DIIS
                PRECONDITIONER FULL_KINETIC
            &END OT
        &END SCF

        &PRINT
            &MULLIKEN
                FILENAME regtest-mul.pop
                !&EACH
                !    corresponding_motion 1
                !&END EACH
            &END MULLIKEN
        &END PRINT
    &END DFT
    &PROPERTIES
        &LINRES
            PRECONDITIONER FULL_ALL
            &LOCALIZE
                EPS_LOCALIZATION 0.75E-4
            &END LOCALIZE
            &EPR
                &PRINT
                    &G_TENSOR
                        FILENAME regtest-gtens
                        &XC
                            &XC_FUNCTIONAL
                                !SECTION_PARAMETERS PBE
                                &XALPHA
                                    XA 0.7
                                &END XALPHA
                            &END XC_FUNCTIONAL
                        &END XC
                    &END G_TENSOR
                &END PRINT
            &END EPR
        &END LINRES
    &END PROPERTIES


&END FORCE_EVAL




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