Computation of the water density distribution at the ice-water interface using the potentials-of-mean-force expansion

The water density distribution at an ice-Ih–water interface is computed by means of the expansion of the n-particle potentials of mean force (PMF) in terms of lower-order PMF’s truncated at the triplet level. Pair and triplet correlations for the simple point-charge water model are computed via Monte Carlo (MC) simulations. The distributions obtained are in very good agreement with extensive MC simulations of the interface. The PMF-expansion technique is orders of magnitude faster than the simulations and provides a powerful tool for the study of complex interfacial phenomena involving aqueous phases.