Pure semiempirical calculation

[shihao]

Dear all,

I'm trying to run semiempirical calculations using CP2K.  The system
has 250 water molecules and uses PBC and NVT ensemble (298.15K).  I
did test runs for only a few time steps and found that the conserved
quantity is not well conserved and the temperature keeps increasing
rapidly (goes up to 2000K).  The input file is attached. Does anyone
have any ideas on what the problem is?  Any help will be appreciated.

Thanks
Shihao


&GLOBAL
  PROGRAM_NAME                 CP2K
  PROJECT_NAME                 wt_bk_01
  RUN_TYPE                     MD
  SEED                         1000
  PREFERRED_FFT_LIBRARY        FFTW
  PRINT_LEVEL                  LOW
  SAVE_MEM
&END GLOBAL

&MOTION
  &MD
    ENSEMBLE                   NVT
    STEPS                      2000
    TIMESTEP                   0.50
    TEMPERATURE                298.15
    &THERMOSTAT
      TYPE                     NOSE
      REGION                   GLOBAL
      &NOSE
        LENGTH                 3
        YOSHIDA                3
        TIMECON                100
        MTS                    2
      &END NOSE
      @INCLUDE run_cp2k.tr1
    &END THERMOSTAT
    &THERMAL_REGION
      @INCLUDE run_cp2k.tr2
      &PRINT
        &TEMPERATURE
          &EACH
            MD                 20
          &END EACH
        &END TEMPERATURE
      &END PRINT
    &END THERMAL_REGION
    &PRINT
      &ENERGY
        &EACH
          MD                   20
        &END EACH
      &END ENERGY
    &END PRINT
  &END MD

  &PRINT
    &RESTART
      &EACH
        MD                     20
      &END EACH
    &END RESTART
    &RESTART_HISTORY           OFF
    &END RESTART_HISTORY

    &TRAJECTORY                SILENT
      FORMAT                   DCD
      &EACH
        MD                     20
      &END EACH
    &END TRAJECTORY
    &VELOCITIES                OFF
    &END VELOCITIES
    &FORCES                    OFF
    &END FORCES
  &END PRINT
&END MOTION

&FORCE_EVAL
  &DFT
    &SCF
      SCF_GUESS                ATOMIC
      EPS_SCF                  1.0E-6
      MAX_SCF                  50
      &OUTER_SCF
        EPS_SCF                1.0E-6
        MAX_SCF                10
      &END OUTER_SCF
      &OT
        PRECONDITIONER         NONE
        MINIMIZER              DIIS
        N_DIIS                 7
      &END OT
      &PRINT
        &RESTART
          &EACH
            MD                 20
          &END EACH
        &END RESTART
        &RESTART_HISTORY       OFF
        &END RESTART_HISTORY
      &END PRINT
    &END SCF

    &QS
      METHOD                   AM1
      EPS_DEFAULT              1.0E-12
      EXTRAPOLATION            PS
      EXTRAPOLATION_ORDER      3
      &SE
      &END SE
    &END QS
    &MGRID
      COMMENSURATE
      CUTOFF                   280
    &END MGRID
    &POISSON
      POISSON_SOLVER           PERIODIC
      PERIODIC                 XYZ
    &END POISSON

    &PRINT
      &E_DENSITY_CUBE
        &EACH
          MD                   20
        &END EACH
      &END E_DENSITY_CUBE
    &END PRINT
  &END DFT

  &SUBSYS
    &CELL
      ABC                      19.574 19.574 19.574
      PERIODIC                 XYZ
    &END CELL
    &TOPOLOGY
      COORDINATE               PDB
      COORD_FILE_NAME          ./run_cp2k.pdb
      PARA_RES                 T
    &END TOPOLOGY
    &KIND                          O
    &END KIND
    &KIND                          H
    &END KIND
  &END SUBSYS
&END FORCE_EVAL