Atomistic simulation of hydroxide ions in inorganic solids

This paper describes the derivation of an empirical interatomic potential for the interaction of hydroxide ions with metal oxides. The model is based on the Born model of solids and its major features are firstly that the OH interaction is principally described by a Morse potential, derived originally by Saul et al. using ab initio Hartree-Fock methods, secondly that the parameters describing the short-range interaction of the hydroxyl oxygen with cations follows the approach suggested by Schroder et al. which ensured that the cation-anion equilibrium bond distances were maintained on modifying the anion charge and thirdly that electronic polarizability on the hydroxyl oxygen ion is included. The utility of this approach is described by applying this model to three systems: hydrogen defects in alpha-quartz; at alpha-quartz and sodalite surfaces; in modelling non-silicate hydroxide crystal structures, that is Mg(OH)(2) and Al(OH)(3).