Finite temperature behavior of H+(H2O)6 and H+(H2O)8

The finite temperature behavior of H+(H2O)(6) and H+(H2O)(8) is investigated by means of parallel tempering Monte Carlo simulations in conjunction with the multistate empirical valence-bond method for describing the interactions. The temperature dependence of the constant volume configurational heat capacity, Cv(T), of H+(H2O)(8) reveals two sharp transitions, whereas that of H+(H2O)(6) is devoid of sharp structure.