Monte Carlo Simulation of M⁺Cl⁻(H₂O)n(M = Li, Na) Clusters–Structures, Fluctuations and Possible Dissolving Mechanism

Monte Carlo simulations of M+Cl− (H2O) n (M = Li, Na) clusters at room temperature using new type of intermolecular potential function were performed to obtain the structural informations under the thermal equilibrium conditions, such as fluctuation of interionic-distance and orientation of water molecules around ion pairs. The lowest-energy geometries of these clusters were water-shared ion pairs, except Li+Cl− (H2O). From Monte Carlo results, we have found that shared water molecules may tend to place between a cation and an anion for their dipole-site stabilization interactions and play an important role for the dissolving process of ion pairs. A possible model for dissolving process of LiCl and NaCl salt into water was proposed.