Molecular dynamics studies of evaporation and condensation coefficients in nucleation theory

A rate theory that accounts for multimolecular addition or loss of molecules from a cluster is developed for the homogeneous nucleation of a liquid from its metastable vapor. Molecular dynamics simulations of Lennard-Jones argon are used to study the evaporation coefficients of Stillinger type clusters. It is shown that steps involving the gain or loss of 2 or 3 atoms at a time make a significant contribution to the dynamics of cluster growth and that these multimolecular steps obey detailed balance. Studies of the lagtime, which to a first approximation should be related to the nucleation rate, shows that ln(t(70)) is proportional to l/ln(2)(S), as predicted by classical nucleation theory.