Energy drift while using constraints with FIST

yimanu duu... at gmail.com
Wed Aug 18 22:37:35 CEST 2010


Hi all,

I want to do qmmm so I am starting with mm equilibration with fist. I
want to fix all bonds involving hydrogen so I am using an HBONDS
section but I get an energy drift. I have played with several
parameters, eg &SPLINE section parametrs, cutoff, force constant for
constraint etc with no solution so any pointers is welcome. Thanks my
input is pasted below and I am using a 3 week old cp2k compile.

Many thanks.

Yimanu

&GLOBAL
  PRINT_LEVEL LOW
  PREFERRED_FFT_LIBRARY  FFTSG
  PROJECT hyp_small
  RUN_TYPE MD
&END GLOBAL

&MOTION
  &MD
    ENSEMBLE   NVT
    STEPS      6000000
    TIMESTEP   0.5
    TEMPERATURE 298.0
    &THERMOSTAT
      TYPE NOSE
      #REGION MASSIVE
      &NOSE
        TIMECON   [wavenumber_t] 1000
      &END NOSE
    &END THERMOSTAT
    &PRINT
      &ENERGY
        FILENAME =hyp_small.md.ener
        &EACH
          MD 1
        &END EACH
      &END ENERGY
      &PROGRAM_RUN_INFO
        &EACH
          MD 1
        &END EACH
      &END PROGRAM_RUN_INFO
    &END PRINT
  &END MD
  &PRINT
    &TRAJECTORY
      FILENAME =hyp_small.md.xyz
        &EACH
          MD 100
        &END EACH
    &END TRAJECTORY
    &RESTART
      FILENAME =hyp_small.md.restart
      BACKUP_COPIES 3
      &EACH
        MD 10
      &END EACH
    &END RESTART
    &RESTART_HISTORY OFF
    &END RESTART_HISTORY
  &END PRINT
#  &CONSTRAINT
#    &FIXED_ATOMS
#       QM_SUBSYS MOLECULAR
#    &END FIXED_ATOMS
#   &HBONDS
#    ATOM_TYPE OW OO CT
#     MOLNAME WAT1 .. WAT541 AHM
#     MOLECULE 1..542
#     &RESTRAINT
#         K [kcalmol] 5.0
#     &END RESTRAINT
#  &END HBONDS
#  &END CONSTRAINT

&END MOTION

&FORCE_EVAL
#  METHOD QMMM
  METHOD FIST
  &MM
    &FORCEFIELD
      parm_file_name model.top
      parmtype AMBER
      VDW_SCALE14 0.50
      EI_SCALE14 0.833333
      &SPLINE
        EMAX_SPLINE     1.0
        RCUT_NB         10.0
	#UNIQUE_SPLINE T
	EMAX_ACCURACY 1.00E-6
	EPS_SPLINE 1.00E-10
      &END SPLINE
    &END FORCEFIELD
    &POISSON
      &EWALD
        EWALD_TYPE spme
        ALPHA .37
        GMAX 31 31 31
      &END EWALD
    &END POISSON
  &END MM
  &DFT
    BASIS_SET_FILE_NAME         GTH_BASIS_SETS
    POTENTIAL_FILE_NAME         POTENTIAL
    WFN_RESTART_FILE_NAME       RESTART
    &MGRID
      CUTOFF 280
      COMMENSURATE
    &END MGRID
    &SCF
      MAX_SCF     50
      EPS_SCF     1.0E-7
      SCF_GUESS   RESTART
      &OUTER_SCF
        EPS_SCF 1.0E-7
        MAX_SCF 10
      &END
      &OT T
        MINIMIZER         DIIS
        N_DIIS            7
      &END OT
      &PRINT
        &RESTART
          FILENAME =RESTART
        &END RESTART
        &RESTART_HISTORY OFF
        &END RESTART_HISTORY
      &END PRINT
    &END SCF
    &QS
      EPS_DEFAULT          1.0E-14
      MAP_CONSISTENT
      EXTRAPOLATION        ASPC
    &END QS
    &XC
#      &XC_GRID
#        XC_SMOOTH_RHO NN10
#        XC_DERIV      SPLINE2_SMOOTH
#      &END XC_GRID
      &XC_FUNCTIONAL BLYP
      &END XC_FUNCTIONAL
#      &vdW_POTENTIAL
#        DISPERSION_FUNCTIONAL PAIR_POTENTIAL
#        &PAIR_POTENTIAL
#           R_CUTOFF 40.0
#           TYPE PAIR_POTENTIAL
#        &END PAIR_POTENTIAL
#      &END vdW_POTENTIAL
    &END XC
#    &POISSON
#      POISSON_SOLVER MT
#      PERIODIC NONE
#      &MT
#        ALPHA 7.0
#         REL_CUTOFF 2.0
#      &END MT
#    &END POISSON
  &END DFT
  &QMMM
    E_COUPL GAUSS
    USE_GEEP_LIB  10
    &CELL
      ABC 16.0 16.0 16.0
      PERIODIC XYZ
    &END CELL
  &PERIODIC
      GMAX 0.5
      &MULTIPOLE
         EWALD_PRECISION 1.0E-6
         RCUT 8.0
      &END MULTIPOLE
  &END PERIODIC
    &QM_KIND C
      MM_INDEX    2 5 8 11 15 18 20 23
    &END QM_KIND
    &QM_KIND N
      MM_INDEX    7
    &END QM_KIND
    &QM_KIND O
      MM_INDEX    6 13 21 22
    &END QM_KIND
    &QM_KIND H
      MM_INDEX    1 3 4 9 10 12 14 16 17 19 24 25 26
    &END QM_KIND
  &END QMMM
  &SUBSYS
    &CELL
      ABC 25.385  25.800  25.556
    &END CELL
    &TOPOLOGY
      CONN_FILE_FORMAT    PSF
      COORD_FILE_FORMAT   PDB
      COORD_FILE_NAME     model.pdb
      CONN_FILE_NAME      model.psf
#      &DUMP_PSF
#        FILENAME ./model.psf
#      &END DUMP_PSF
    &END TOPOLOGY
    &KIND OO
      ELEMENT O
    &END KIND
    &KIND C
      BASIS_SET DZVP-GTH
      POTENTIAL GTH-BLYP-q4
    &END KIND
    &KIND H
      BASIS_SET DZVP-GTH
      POTENTIAL GTH-BLYP-q1
    &END KIND
    &KIND O
      BASIS_SET DZVP-GTH
      POTENTIAL GTH-BLYP-q6
    &END KIND
    &KIND N
      BASIS_SET DZVP-GTH
      POTENTIAL GTH-BLYP-q5
    &END KIND
  &END SUBSYS
  &PRINT
    &PROGRAM_RUN_INFO
      &EACH
        MD 1
      &END EACH
    &END PROGRAM_RUN_INFO
  &END PRINT

&END FORCE_EVAL

#&EXT_RESTART
#  RESTART_FILE_NAME hyp_small.md.restart
#  RESTART_DEFAULT    F
#  RESTART_POS        T
#&END EXT_RESTART




More information about the CP2K-user mailing list