Bias

PLUMED allows you to run a number of enhanced sampling algorithms. The list of enhanced sampling algorithms contained in PLUMED is as follows:

ABMD	Adds a ratchet-and-pawl like restraint on one or more variables.
BIASVALUE	Takes the value of one variable and use it as a bias
EXTENDED_LAGRANGIAN	Add extended Lagrangian.
EXTERNAL	Calculate a restraint that is defined on a grid that is read during start up
LOWER_WALLS	Defines a wall for the value of one or more collective variables, which limits the region of the phase space accessible during the simulation.
METAD	Used to performed MetaDynamics on one or more collective variables.
MOVINGRESTRAINT	Add a time-dependent, harmonic restraint on one or more variables.
PBMETAD	Used to performed Parallel Bias MetaDynamics.
RESTRAINT	Adds harmonic and/or linear restraints on one or more variables.
UPPER_WALLS	Defines a wall for the value of one or more collective variables, which limits the region of the phase space accessible during the simulation.

Methods, such as METAD or PBMETAD, that work by introducing a history dependent bias can be restarted using the RESTART keyword

You can also use PLUMED in conjunction with VMD's interactive MD module by taking advantage of the IMD action.