A coupled RISM/MD or MC simulation methodology for solvation free energies

Abstract

We propose a new computational methodology that couples reference interaction site model (RISM) and molecular dynamics (MD) or Monte Carlo (MC) simulation methods for determination of solvation free energies. We employ the RISM formulation of solvation free energy. The correlation functions entering this expression are derived from radial distribution functions supplied by MD or MC simulations, instead of coming from simultaneous solution of the RISM and hyper-netted chain equations. We apply this approach to determining free energies of solvation for several small molecules. Our results are in good agreement with experimental values, demonstrating the potential of this method for applications to larger systems.