The lattice dynamics of clathrate hydrates. An incoherent inelastic neutron scattering study

Abstract The vibrational densities of states in the lattice translation region below 130 cm −1 (3 THz) for structure I xenon hydrate and structure II krypton hydrate have been determined from incoherent inelastic neutron scattering experiments. The main features in the lattice vibrations are found to shift to higher frequencies when compared to ice I h . The shift is due to repulsive interactions between the water molecules and the guests which help to stabilize the hydrate structure. The experimental observation is in good accord with that predicted from earlier molecular dynamics calculations.