&FORCE_EVAL
  METHOD FIST
  &MM
    &FORCEFIELD
      parm_file_name ../sample_pot/nh3.pot
      parmtype CHM
    &END FORCEFIELD
    &POISSON
      &EWALD
        EWALD_TYPE spme
        ALPHA .44
        GMAX 30
        O_SPLINE 6
      &END EWALD
    &END POISSON
  &END MM
  &SUBSYS
    &CELL
      ABC 10.0 10.0 10.0
    &END CELL
    &TOPOLOGY
      CONN_FILE_NAME ../sample_psf/nh3.psf
      CONNECTIVITY UPSF
      COORD_FILE_NAME ../sample_pdb/nh3_1mol.pdb
      COORDINATE pdb
    &END TOPOLOGY
    &COLVAR
       &DISTANCE_POINT_PLANE
          ATOMS_PLANE 2 3 4
          ATOM_POINT 1
       &END DISTANCE_POINT_PLANE
    &END COLVAR
  &END SUBSYS
&END FORCE_EVAL
&GLOBAL
  PROJECT nh3-meta-4
  RUN_TYPE md
&END GLOBAL
&MOTION
  &MD
    ENSEMBLE NVE
    STEPS 100
    TIMESTEP 0.5
    TEMPERATURE 300.0
    TEMP_TOL 10.0
  &END MD
  &FREE_ENERGY
    &METADYN
      DO_HILLS
      LAGRANGE F
      NT_HILLS 3
      WW 1.0e-3
      &METAVAR
        SCALE 0.02
        COLVAR 1
        &WALL
          TYPE GAUSSIAN
          POSITION -0.5
          &GAUSSIAN
             WW 0.5
             SIGMA 0.05
          &END
        &END
        &WALL
          TYPE GAUSSIAN
          POSITION -1.0
          &GAUSSIAN
             WW 0.5
             SIGMA 0.05
          &END
        &END
      &END METAVAR
    &END METADYN
  &END
&END MOTION
