Methanol-water mixtures: a microsolvation study using the effective fragment potential method.

The formation process of methanol-water mixtures, (MeOH/H2O)n, n = 2, 3,..., 8 is studied at the molecular level using the general effective fragment potential (EFP2) method and second-order perturbation theory (MP2). Extensive Monte Carlo/simulated annealing global optimizations were used to locate global minimum structures for each n, for both homo and hetero clusters. Mixing at the microscopic level was investigated, and some general conclusions about the microsolvation behavior of these mixtures are presented. For all of these clusters, incomplete mixing is observed at the molecular level. Low-energy (MeOH/H2O)n clusters retain much of their initial structure in the global minima of the mixed clusters.