ULTRAFAST SOLVATION DYNAMICS - MOLECULAR EXPLANATION OF COMPUTER-SIMULATION RESULTS IN A SIMPLE DIPOLAR SOLVENT

Recently Perera and Berkowitz [J. Chem Phys. 96, 3092 (1992)] and Neria and Nitzan [J. Chem. Phys. 96, 5433 (1992)] carried out computer simulations of solvation dynamics of an ion in dense Stockmayer liquids. Both the simulations observed an ultrafast component which decays in a few tens of femtoseconds with a Gaussian time dependence. This is followed by a slow exponential-like decay with a time constant of a few picoseconds. It is shown here that many of the simulation results can be explained very well from a first principles theory with no adjustable parameter.