Modeling metal dissolution in aqueous electrolyte: Hartree-fock and molecular dynamics calculations

Aspects of the motion of atoms on metal surfaces during dissolution in aqueous electrolyte have been studied by two quantum computational methodologies. First INDO, the semi-empirical Hartree-Fock intermediate neglect of differential overlap method, was used to explore the potential energy surface of adsorbed water molecules and to speculate, using simple cluster models, on the reaction path followed by metal ions leaving the surface. Examples explore the potential energy curve for a metal atom leaving the surface and entering solvation cages of different geometry and show that the proximity of a local anion is crucial. Second a simplified Car-Parinello dynamics is used to examine dissolution in the time range 1 to 20ps. It is used to follow the development of the solvation shell around a departing ion and to calculate the potential of mean force acting on the ion.