A possible nonpolar solvation mechanism at an intermediate time scale: the solvent-cage expansion

Through studying the so-called `epsilonʹ nonpolar solvation model, we propose that the expansion of the solvent cage, which is composed of the solvents at the vicinity of the first maximum of the solute-solvent radial distribution function, might be a possible solvation mechanism at a time scale between inertial motions and structural relaxation. The expansion is triggered by the strong repulsion between the solute and its neighboring solvents, originally inside the cage. This intermediate mechanism is found to be the cause for the bump following the ultrafast decay in the solvation time correlation functions of the `epsilonʹ model at low densities.