On the correlation between the step rates and the diffusivities of guest molecules in microporous crystals

A general expression for the correlation between the elementary steps of molecular propagation and the diffusivities in microporous crystals is derived. For certain types of framework, on the basis of this correlation the main elements of the tensor of molecular diffusion may be shown to depend on each other. Both PFG NMR measurements and MD calculations confirm the predicted interdependence.