Investigation of Water Clusters Containing OH~- and H_3O~+ Ions in Atmospheric Conditions. A Molecular Dynamics Simulation Study

摘要

Water clusters, formed on the aqueous ions H~+, OH~-, or H_3O~+ are investigated using the molecular dynamics simulation method. Temperature dependence of various cluster properties is studied from 150 to 300 K. The dependence of both the cluster structure and its thermodynamic characteristics on the cluster size (N) is analyzed at 300 K. It is found, based on the energy criteria, that the cluster around the hydronium (H_3O~+) ion is more stable for all cluster sizes, while the work-of-formation criteria predicted the water cluster on the protonated ion to be more stable when N > 30. On the bases of work-of-cluster-formation and its size dependent, the nucleation barrier was found to be lower for clusters around hydronium ion than those formed around the hydroxyl ions.