THEORETICAL-STUDY ON BINDING ENTHALPIES AND POPULATIONS OF ISOMERS OFCL-(H2O)N CLUSTERS AT ROOM-TEMPERATURE

The Monte Carlo simulations were performed for Cl-(H2O). (n = 1-8) at room temperature. The calculated enthalpy changes were in reasonable a greement with the experiments. The O-O radial distribution function of n = 2 clearly showed that the population of the ion-centered structur e was larger than that of the pyramidal structure, though the former w as energetically less stable than the later by 2 kcal/mol. The mole fr actions of isomers were estimated by the partition function constructe d using a simple theoretical model. The results suggest that the major isomer at room temperature is not necessarily the energetically most stable one, but the entropy-favored one.