Efficient free-energy calculations by the simulation of nonequilibrium processes

Discusses a particular application of computational physics: the calculation of thermodynamic properties by computer simulation methods. More specifically, we focus on one of the most difficult tasks in this context: the estimation of free energies in problems such as the study of phase transformations in solids and liquids, the influence of lattice defects on the mechanical properties of technological materials, the kinetics of chemical reactions, and protein-folding mechanisms in biological processes. Because the free energy plays a fundamental role, the development of efficient and accurate techniques for its calculation has attracted considerable attention during the past 15 years and is still an active field of research. We discuss some general aspects of equilibrium and nonequilibrium approaches to free-energy measurement and present the “reversible scaling” technique which we have recently developed