Multicanonical molecular dynamics by variable-temperature thermostats   and variable-pressure barostats
  Sampling from flat energy or density distributions has proven useful in equilibrating complex systems with large energy barriers. Several thermostats and barostats are presented to sample these flat distributions by molecular dynamics. These methods use a variable temperature or pressure that is updated on the fly in the thermodynamic controller. These methods are illustrated on a Lennard-Jones system and a structure-based model of proteins. 
Cheng Zhang, Michael W. Deem
physics.comp-ph cond-mat.stat-mech