Use of a Dissociative Potential to Simulate Hydration of Na+ and Cl− ions

We have developed interatomic interaction parameters for Na+ and Cl− hydration using the dissociative water potential of Mahadevan and Garofalini [J. Phys. Chem. B 2007, 111, 8919] suitable for molecular dynamic simulations. Simulations were performed for small ion−water clusters Na(H2O) n + (n = 1−6) and Cl(H2O) m − (m = 1−5), as well as dilute aqueous solutions of the ions in water, reproducing the structure and energies found in the literature. A simulation of an HCl molecule in water demonstrated the dissociation of the molecule. The Na+ and Cl− ion−ion interaction parameters also reproduce the energy and density of crystalline NaCl. A series of simulations of NaCl at progressively increasing temperatures from 300 to 1400 K produced solid densities varying by less than 1% from experiment.