MONTE CARLO SIMULATIONS OF SMALL H 2SO4-H2O CLUSTERS*

Abstract- Small binary clusters of water and sulfuric acid are simulated with effective atom-atom pair potentials modeled after empirical and quantum mechanical studies of the H2SO4-H2O system. The effective potentials assume rigid H 2O an SO 4-- structures with two unconstrained H+ ions free to bond with either species. The Monte Carlo simulations provide information about size dependent cluster structure, interaction energies, free energies, RMS displacements, and specific heats of the molecules in the cluster. The goals of this work are to generate Helmholtz free energy differences for constant concentration, adjacent sized clusters and estimate effective small binary cluster surface tension. Preliminary results for the free energy differences are given