Artificial boundary potentials (walls)

The following options are useful to define restraints (confining potentials) for this colvar. To apply moving restraints, or restraints to more than one colvar simultaneously, a more convenient option is to use the harmonic bias (13.5.3).

• lowerWallConstant $\langle\,$ Lower wall force constant (kcal/mol)$\,\rangle$
  Context: colvar
  Acceptable values: positive decimal
  Description: Defines the force constant for a confining restraint on the colvar, in the form of a ``half-harmonic'' potential. The potential starts at lowerWall if it is defined, or lowerBoundary otherwise. The energy unit of the constant is kcal/mol, while the spatial unit is that of the colvar.

• lowerWall $\langle\,$ Position of the lower wall$\,\rangle$
  Context: colvar
  Acceptable values: decimal
  Default value: lowerBoundary
  Description: Defines the value below which a confining restraint on the colvar is applied, in the form of a ``half-harmonic'' potential. Allows to use a different position of the wall than lowerBoundary.

• upperWallConstant $\langle\,$ Upper wall force constant (kcal/mol)$\,\rangle$
  Context: colvar
  Acceptable values: positive decimal
  Description: Analogous to lowerWallConstant.

• upperWall $\langle\,$ Position of the upper wall$\,\rangle$
  Context: colvar
  Acceptable values: decimal
  Default value: upperBoundary
  Description: Analogous to lowerWall.