Extensive simulations of methane diffusion in ZK4 cubic zeolite were performed by using a model which included the vibrations of the silicate framework. In order to understand the role of the lattice dynamics in assisting the diffusive motion of the sorbed molecules, a study was also made of the same system in the rigid framework approximation. Even more evidently than in the case of zeolite structures where the micropores were essentially cylindrical, the framework oscillations were confirmed to be an essential factor in determining the magnitude of the intracrystalline diffusion coefficient.

Molecular Dynamics Investigation of the Diffusion of Methane in a Cubic Symmetry Zeolite of Type ZK4. P.Demontis, G.B.Suffritti: Chemical Physics Letters, 1994, 223[4], 355-62

Figure 19

Conductivity of Y-Type Zeolites

(a: NaY. b: HY)