QUANTUM SIMULATION OF AQUEOUS IONIC CLUSTERS

Classical and quantum (Path Integral Monte Carlo) simulations are perf ormed at several temperatures (i.e., 100, 200, and 300 K) on the ionic clusters Cl-(H2O)(n), n 1-6 to determine the importance of quantum ef fects on nuclear motion. The polarizable water and ion-water potential models are used to describe water-water and ion-water interactions. C omparison of classical and quantum binding enthalpies. indicate that t he quantum effect is significant at lower temperature (i.e., at 100 K) ; the difference can amount up to 20% of the total energy. The calcula ted quantum radial distribution functions, due to delocalization of qu antum nuclei, are less structured and slightly shifted outward compare d to the corresponding classical description.