[CP2K:3255] Possible QM/MM Bug

[Teodoro Laino]

Hi,

can you please also post the output file?
Thank you.

Teo

On May 18, 2011, at 8:25 PM, Isaiah Sumner wrote:

> Hi,
>  I have been trying to run parallel QM/MM calculations and have run
> into a problem. I get different energies depending on how many
> processors I use. The energy differences are significant. For example,
> using 24 procs on a Cray XE6, I get,
> 
> ENERGY| Total FORCE_EVAL ( FIST ) energy (a.u.):
> 6.710514008036768
> ENERGY| Total FORCE_EVAL ( QS ) energy (a.u.):
> -64.534140477272018
> ENERGY| Total FORCE_EVAL ( QMMM ) energy (a.u.):
> -55.496751397737185
> 
> but 48 procs gives,
> 
> ENERGY| Total FORCE_EVAL ( FIST ) energy (a.u.):
> 6.710514008036785
> ENERGY| Total FORCE_EVAL ( QS ) energy (a.u.):
> -64.482262744620684
> ENERGY| Total FORCE_EVAL ( QMMM ) energy (a.u.):
> -55.444873665085836
> 
> The energy difference always comes in at the QS calculation. And it
> seems to only occur if I use electrostatic coupling. This error
> persists over different machines with different architectures and
> compilers. Is this a known problem or have I made a mistake somewhere?
> 
> Thanks,
>   Isaiah
> 
> My input is the one given by Pauwels Ewald in this forum as an
> example input. I've replicated the input below.
> 
> &FORCE_EVAL
>  METHOD QMMM
>  &DFT
>    BASIS_SET_FILE_NAME GTH_BASIS_SETS
>    POTENTIAL_FILE_NAME GTH_POTENTIALS
>    &MGRID
>      COMMENSURATE
>      CUTOFF 280
>    &END MGRID
>    &QS
>     METHOD GPW
>     EXTRAPOLATION PS
>     EXTRAPOLATION_ORDER 2
>    &END QS
>    &SCF
>      EPS_SCF 5.0E-7
>      MAX_SCF 20
>      SCF_GUESS RESTART
>      &OUTER_SCF
>        EPS_SCF 5.0E-7
>        MAX_SCF 20
>      &END
>      &OT
>        MINIMIZER DIIS
>        PRECONDITIONER FULL_ALL
>        STEPSIZE 0.10
>      &END OT
>    &END SCF
>    &XC
>      &XC_FUNCTIONAL BLYP
>      &END XC_FUNCTIONAL
>    &END XC
>  &END DFT
>  &MM
>    &FORCEFIELD
>      PARMTYPE CHM
>      PARM_FILE_NAME par_all27_prot_na.prm
>      EI_SCALE14 1.0
>      VDW_SCALE14 1.0
>      &SPLINE
>         EMAX_SPLINE 1.0
>         RCUT_NB 10.0
>      &END SPLINE
>    &END FORCEFIELD
>    &NEIGHBOR_LISTS
>      GEO_CHECK F
>    &END NEIGHBOR_LISTS
>    &POISSON
>      &EWALD
>        EWALD_TYPE spme
>        ALPHA .4
>        GMAX 27
>      &END EWALD
>    &END POISSON
>  &END MM
>  &SUBSYS
>    &CELL
>      ABC 20.0 20.0 20.0
>    &END CELL
>    &TOPOLOGY
>      CONN_FILE TAwater.psf
>      CONNECTIVITY PSF
>      COORD_FILE_NAME TAwater.pdb
>      COORD_FILE_FORMAT PDB
>    &END TOPOLOGY
>    &KIND Cqm
>      ELEMENT C
>      BASIS_SET DZVP-GTH
>      POTENTIAL GTH-BLYP-q4
>    &END KIND
>    &KIND Oqm
>      ELEMENT O
>      BASIS_SET DZVP-GTH
>      POTENTIAL GTH-BLYP-q6
>    &END KIND
>    &KIND Nqm
>      ELEMENT N
>      BASIS_SET DZVP-GTH
>      POTENTIAL GTH-BLYP-q5
>    &END KIND
>    &KIND Hqm
>      ELEMENT H
>      BASIS_SET DZVP-GTH
>      POTENTIAL GTH-BLYP-q1
>    &END KIND
>    &KIND H_LINK
>      ELEMENT H
>      BASIS_SET DZVP-GTH
>      POTENTIAL GTH-BLYP-q1
>    &END KIND
>  &END SUBSYS
>  &QMMM
>    &CELL
>      ABC 10.0 10.0 10.0
>    &END CELL
>    ECOUPL GAUSS
>    NOCOMPATIBILITY
>    USE_GEEP_LIB 12
>    NOCENTER0 FALSE
>    NOCENTER TRUE
>    &QM_KIND Cqm
>      MM_INDEX 15 17 21
>    &END QM_KIND
>    &QM_KIND Oqm
>      MM_INDEX 12 22
>    &END QM_KIND
>    &QM_KIND Nqm
>      MM_INDEX 13
>    &END QM_KIND
>    &QM_KIND Hqm
>      MM_INDEX 14 16 18 19 20
>    &END QM_KIND
>    &LINK
>      QM_INDEX 13
>      QM_KIND H
>      MM_INDEX 11
>      LINK_TYPE IMOMM
>      ALPHA_IMOMM 1.50
>    &END LINK
>    &LINK
>      QM_INDEX 21
>      QM_KIND H
>      MM_INDEX 26
>      LINK_TYPE IMOMM
>      ALPHA_IMOMM 1.50
>    &END LINK
>    &PERIODIC
>      GMAX .1
>      &MULTIPOLE
>        RCUT 10.0
>      &END MULTIPOLE
>    &END PERIODIC
>    &PRINT
>      &QMMM_LINK_INFO
>      &END QMMM_LINK_INFO
>      &POTENTIAL
>      &END POTENTIAL
>    &END PRINT
>  &END QMMM
> &END FORCE_EVAL
> &GLOBAL
>  PREFERRED_FFT_LIBRARY FFTSG
>  EXTENDED_FFT_LENGTHS T
>  PROJECT TA
>  RUN_TYPE GEO_OPT
>  PRINT_LEVEL LOW
> &END GLOBAL
> &MOTION
>  &GEO_OPT
>    OPTIMIZER LBFGS
>    MAX_ITER 4000
>  &END GEO_OPT
> &END MOTION
> 
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