Numerical simulations of solvation dynamics in electrolyte solutions

Recent experimental studies of solvation dynamics in electrolyte solutions indicate the existence of a slow dynamical component associated with the salt ions. This contribution cannot be accounted for by the Debye-Falkenhagen theory of ionic atmosphere response. Molecular dynamics simulations of solvation dynamics in a simple model (Stockmayer solvent containing spherical ions) of electrolyte solution are presented. The simulations confirm the interpretation that the slow dynamical component is primarily an outcome of ion exchange between the first solvation shell about the solute and the solution bulk. The simulations also indicate the highly correlated motion between the salt ions and the solvent molecules.