Mechanisms for Stabilising Water Clathrates

Molecular dynamics computer simulations are used to examine various possible mechanisms for stabilising water clathrates. It is found that the attractive interactions between guest and host molecules are not sufficient to explain the clathrate's stability; nor is there any significant dynamic coupling between the guest and host molecules in the clathrate. Instead, it appears that the repulsive guest-host interactions provide the mechanical stability of the clathrate, and that they are even sufficient to define its structure. Some of the thermodynamic implications of these observations are discussed.