Quantities relevant to the chemical and tracer diffusion coefficients, namely the tracer correlation factor, the mobility correlation factor and the site-availability factor were calculated for an interacting lattice gas model using a Monte Carlo method. The origin and nature of the mobility correlation factor was discussed. Calculations were performed for diffusion by nearest-neighbor hopping between the tetrahedral sites in a BCC host, for each of four different site-blocking models (no double occupancy, multiple blocking to first, second or third neighbor). Comparisons were made with previous experimental work on NbHx and TaHx.

Tracer and Chemical Diffusion of Hydrogen in BCC Metals. D.A.Faux, D.K.Ross: Journal of Physics C, 1987, 20[10], 1441-57