A probabilistic protocol which made possible the calculation of the diffusivity of light gases in amorphous materials from limited Monte Carlo and molecular dynamics data was presented. Diffusion coefficients were calculated for helium and methane in polystyrene, and for helium, neon, and methane in three pairs of polysulfone isomers. Results included diffusion coefficients as small as 10-9cm2/s and were in good agreement with results obtained from traditional molecular dynamics and with available experimental data.

Gas Diffusion in Glasses via a Probabilistic Molecular Dynamics. Willmore, F.T., Wang, X.Y., Sanchez, I.C.: Journal of Chemical Physics, 2007, 126[23], 234502