IONIC HYDRATION NEAR PLATINUM AND LIQUID MERCURY SURFACES

Molecular Dynamics simulations of a lithium and an iodide ion near a w ater-platinum and a water-liquid mercury interface have been performed where the ion-metal and the water-metal potentials are derived from a b initio calculations of an ion or a water molecule and a metal cluste r consisting of five to ten atoms. The flexible BJH water model and a mercury-mercury potential derived from pseudopotential theory are empl oyed. The other potentials are based on ab initio calculations. The st ructural properties at the interfaces are described by the ion. oxygen . hydrogen. and mercury density profiles and the ion-oxygen, ion-hydro gen, and ion-mercury radial distribution functions. The mercury-mercur y potential allows the analysis of the ion-induced rearrangements of t he mercury atoms al the surface. The spectral densities of the hindere d translational motions of the ions parallel and perpendicular to the two surfaces are reported.