(602a) Probabilistic Molecular Dynamics: Playing Dice with Molecules

A multiscale probability model is developed which makes possible the simulation of diffusion processes on comparatively larger time and length scales. By taking advantage of differences in the time and length scales associated with the motion of small diffusants vs the motion of a host glassy polymeric material, the model simulates behaviors on the most appropriate time and length scales. Simulations have been run for small molecule diffusion in polymers, measuring diffusivities on the order of 10-9 cm2/s in good agreement with experimental results. Results also include measurements of the self-diffusion coefficients in a Lennard-Jones fluid.