The frequency dependent conductivity of electrolyte solutions

The frequency dependent conductivity, σ(ω), of model electrolyte solutions is investigated employing molecular dynamics simulations. Approximate analytical theories are also derived and evaluated. It is found that σ(ω) is generally not a simple function and that its detailed frequency dependence contains much useful information about the structure and dynamics of ionic solutions. By varying molecular and state parameters such as the dipole moment and moment of inertia of the solvent, the ionic charge, the solution density, etc., we are able to obtain a physical interpretation of the behavior of σ(ω). For example, very interesting dynamical solvation effects as well as features associated with ion pairs are identified and described.