QUANTUM SIMULATION OF AQUEOUS IONIC CLUSTERS

Classical and quantum (Path Integral Monte Carlo) simulations are performed 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 effects on nuclear motion. The polarizable water and ion-water potential models are used to describe water-water and ion-water interactions. Comparison of classical and quantum binding enthalpies. indicate that the quantum effect is significant at lower temperature (i.e., at 100 K); the difference can amount up to 20% of the total energy. The calculated quantum radial distribution functions, due to delocalization of quantum nuclei, are less structured and slightly shifted outward compared to the corresponding classical description.