Potential lattice dynamical simulations of ice

Abstract

Lattice dynamical calculations have been carried out for ice Ih, ice XI, ice II and ice VIII using seven rigid pair-wise potentials and a M-point polarizable potential that is a modification of the potential constructed by Dang and Chang [J. Chem. Phys. 106 (1997) 8149]. It was found that the M-point polarizable potential gives out a wide range of hydrogen bonds and a narrow librational band. MCY makes stretching and bending interactions too weak and it gives O–O bond lengths too long (∼5%) so its lattice densities are obviously lower than other potential lattices or experimental values. Other classic potentials (BF, SPC, Rowlinson, TIP3P, TIP4P and TIPS2) produce reasonable results and slightly short O–O bond lengths. The mean two-body interaction energy of M-point polarizable potential is −0.370 eV/molecule and the mean polarizable energy is −0.180 eV/molecule. Nonadditive energy takes about 32.7% of total ice Ih lattice energy, which is less than Molecular Dynamical result 39% for liquid.