Hydrate crystal cells—structures I, II, and

Crystal properties of si, sll, and sH are given in Table 2.2a. Table 2.2b lists the atomic coordinates for these structures, which will enable the advanced reader to generate computer models of the hydrate crystals. The contrast of si and sll structures is obtained by linking the basic 512 cavity in two different ways to achieve fourfold hydrogen bonds. All modes of associating pentagonal 

Lattice description Primitive Face centered Hexagonal 

Atomic positions indicate hie Wyckoff letter in parentheses. 

Davidson and Ripmeester (1984) discuss the mobility of water molecules in the host lattices, on the basis of NMR and dielectric experiments. Water mobility comes from molecular reorientation and diffusion, with the former being substantially faster than the water mobility in ice. Dielectric relaxation data suggest that Bjerrum defects in the hydrate lattice, caused by guest dipoles, may enhance water diffusion rates. 

Jeffrey s (1984) List of a Series of Seven Hydrate Crystal Structures 

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