a dual control volume grand canonical molecular dynamics technique simulates the diffusion of gas in a cylindrical pore. This allowed spatial variation of chemical potential and hence an accurate simulation of steady state pressure driven diffusion. The molecular sieving nature of microporous imogolite models and the Knudsen effect were compared with experimental data.

Molecular Dynamics Computer Simulations of Diffusion in Porous Silicates. Heffelfinger, G.S., Pohl, P.I., Frink, L.J.D.: Materials Research Society Symposium - Proceedings, 1995, 366, 225-30