Optimized free-energy evaluation using a single reversible-scaling simulation

We present a method, for highly efficient free-energy calculations by means of molecular dynamics and Monte Carlo simulations, which is an optimized c ombination of coupling parameter and adiabatic switching formalisms. This a pproach involves dynamical reversible scaling of the potential energy funct ion of a system of interest, and allows accurate determination of its free energy over a wide temperature interval from a single simulation. The metho d is demonstrated in two applications: crystalline Si at zero pressure and a fee nearest-neighbor antiferromagnetic Ising model.