Jumps in total energy

LS laksh... at gmail.com
Thu Jul 28 20:01:29 CEST 2011


Hi,

I am performing an NVE simulation of an isolated molecule. I use the
Wavelet Poisson solver and have the center coordinates keyword as
true. I find that every time I restart the calculation (due to time-
outs of the computing system here), I see jumps in the Conserved
Quantity. Sometimes the jumps are as large as 0.2 hartrees. I
understand that the jumps in energy happen because the program centers
the system during the restart and wavelet poisson solver is not
translational invariant. But is such a  jump in energy considered
reasonable?

I am attaching my input file below.

Thanks
LS

------------------------------------------------------------------------------------------
&GLOBAL
  PROJECT md-1
  RUN_TYPE MD
  PRINT_LEVEL MEDIUM
  WALLTIME 5.95000000E+05
&END GLOBAL

&EXT_RESTART
RESTART_FILE_NAME  md-1.restart
&END EXT_RESTART

&MOTION
  &MD
    ENSEMBLE NVE
    STEPS 100000
    TIMESTEP 0.5
   &PRINT
     FORCE_LAST .TRUE.
   &END PRINT
   &END MD
  &PRINT
  &RESTART
  ADD_LAST NUMERIC
  &END RESTART
  &END PRINT
 &END MOTION


&FORCE_EVAL
  METHOD Quickstep
  &DFT
    BASIS_SET_FILE_NAME ~/cp2k/tests/QS/GTH_BASIS_SETS
    POTENTIAL_FILE_NAME ~/cp2k/tests/QS/POTENTIAL
    UKS
    &MGRID
      CUTOFF 400
      NGRIDS 4
      REL_CUTOFF 25
    &END MGRID
    &QS
      EPS_DEFAULT 1.0E-12
      EPS_GVG 1.0E-6
      EPS_PGF_ORB 1.0E-6
    &END QS
    &SCF
    EPS_SCF 1.0E-6
    MAX_SCF 500
      SCF_GUESS atomic
      &OT ON
        MINIMIZER DIIS
       PRECONDITIONER FULL_ALL
      &END OT
    &END SCF
    &XC
      &XC_FUNCTIONAL BLYP
      &END XC_FUNCTIONAL
    &END XC
   &POISSON
   POISSON WAVELET
   PERIODIC NONE
   &END POISSON
  &END DFT
  &SUBSYS
   &TOPOLOGY
    &CENTER_COORDINATES T
    &END CENTER_COORDINATES
    &END TOPOLOGY
    &CELL
      PERIODIC NONE
      ABC 30.000 30.000 30.000
    &END CELL
     &COORD
     &END COORD
    &VELOCITY
   &END VELOCITY
    &KIND H
      BASIS_SET DZVP-GTH
      POTENTIAL GTH-BLYP-q1
    &END KIND
    &KIND C
      BASIS_SET DZVP-GTH
      POTENTIAL GTH-BLYP-q4
    &END KIND
    &KIND O
      BASIS_SET DZVP-GTH
      POTENTIAL GTH-BLYP-q6
    &END KIND
    &KIND Na
      BASIS_SET DZVP-GTH
      POTENTIAL GTH-BLYP-q9
    &END KIND
  &END SUBSYS
&END FORCE_EVAL




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