QUANTIZED WATER CLUSTERS AROUND APOLAR MOLECULES

In order to understand the mechanism of gas hydrate kinetics and to ex plore the existance of other new cavities in the hydrate structure, we have used Molecular Dynamics (MD) simulation to study a system compri sing two Lennard-Jones particles and 214 water molecules. Equilibrium structure and properties of twelve cases have been investigated. Our f indings were as follows: Apolar molecules promote spherical liquid wat er clusters in a hydrate-like labile cavity. The size of the cavity an d the coordination number is dependent upon the size of the apolar mol ecule. The coordination number of water molecules is quantized in jump s of four. Similarities are observed between the labile cavities and c avities in solid hydrates and in other chemical structures such as Buc kminsterfullerene. Such a simulation procedure suggests the possibilit y of other clusters which may exist in yet-to-be-found hydrates. A sep arate question involves whether such suggested cavities can be combine d with other cavities into a space-filling crystal.