Ion Hydration Under Pressure: A Molecular Dynamics Study

This study is intended to elucidate the role of pressure on the hydration behaviour of ions in aqueous solutions. Molecular dynamics simulations were performed for systems modelling CsF, CsCl, CsBr, and CsI aqueous solutions under ‘normal’ (E{5} Pa, 298 K) and ‘high pressure’ (4E{9} Pa, 500 K) conditions. Structural details are discussed in terms of radial distributions functions, coordination numbers, and instantaneous configurations of the ionic hydration shells. The dynamic properties studied include the velocity autocorrelation functions and self-diffusion coefficients of the ions for both pressure regimes. The results indicate strong changes in the hydration behaviour and mobility of the ions.