
&FORCE_EVAL
  METHOD FIST
  &MM
    &FORCEFIELD
      &spline
       rcut_nb 6.9
      &end
      parm_file_name ../sample_pot/charmm.pot
      parmtype CHM
      &CHARGE
        ATOM NH3
        CHARGE -1.14
      &END CHARGE
      &CHARGE
        ATOM HC
        CHARGE 0.38
      &END CHARGE
    &END FORCEFIELD
    &POISSON
      &EWALD
        EWALD_TYPE ewald
        ALPHA .5
        GMAX 21
      &END EWALD
    &END POISSON
  &END MM
  &SUBSYS
    &CELL
      ABC 13.858 13.858 13.858
    &END CELL
    &TOPOLOGY
      COORD_FILE_NAME ../sample_pdb/NH3_1.pdb
      COORDINATE PDB
    &END TOPOLOGY
  &END SUBSYS
&END FORCE_EVAL
&GLOBAL
  PRINT_LEVEL LOW
  PROJECT NH3_OPT
  RUN_TYPE GEO_OPT
&END GLOBAL
&MOTION
  &GEO_OPT
    OPTIMIZER BFGS
    MAX_ITER 50
    &BFGS
      &RESTART
      &END
    &END
  &END
  &PRINT
    &RESTART
      &EACH
        GEO_OPT 1
      &END
    &END
  &END
&END MOTION
