Free Energy Calculations with Reduced Potential Cutoff Radii.

The Jarzynski Equality, the Crooks Fluctuation Theorem, and the Maximum Likelihood Estimator use a nonequilibrium approach for the determination of free energy differences due to a change in the state of a system. Here, this approach is used in combination with a novel transformation algorithm to increase computational efficiency in simulations with interacting particles, without losing accuracy. The algorithm is shown to work well for a Lennard-Jones fluid undergoing a change in density over three very different density ranges, and for the systems considered the algorithm demonstrates computational savings of up to approximately 90%. The results obtained directly from the Jarzynski Equality and from the Maximum Likelihood Estimator are also compared.