SOLVATION DYNAMICS IN HARD-SPHERE SOLVENTS

The time correlation function for the solvation energy fluctuation is calculated in context of a hard-sphere kinetic theory. The theory has three ingredients: a frequency measuring the thermal fluctuations in t he potential, a frequency measuring the rate of passage of a solvent-s olvent pair through the interaction region, and a memory function repr esenting the longer time dynamics associated with particle recollision s. The calculated time correlation function is determined wholly in te rms of hard-sphere properties, and when compared with a recent molecul ar dynamics simulation, the agreement is surprisingly good. The presen ce of fully correlated recollisions is made known by the appearance of a plateau in the time correlation function. (C) 1995 American Institu te of Physics.