The self-diffusion of Na+ in hydrated natural mordenite was studied. From the variation of the self-diffusion coefficient with temperature, the energy of activation and the pre-exponential factor for the self-diffusion process were calculated from the Arrhenius equations:

D(cm2/s) = 4.89 x 10-7exp[-8.74(kcal/mol)/RT]

L.V.C.Rees, A.Rao: Transactions of the Faraday Society, 1966, 62, 2103-10