It was noted that H diffusion through the metal was one of the rate-determining steps for the sorption kinetics of Mg. Using known Gibbs free energies for the Mg-H system, calculations were made of the concentration (x) of H in MgHx in equilibrium with MgH2. Thus, x was equal to 1.13 x 10-3 at 673K. Using an ab initio dynamic simulation, the position of H in Mg (mostly tetrahedral sites), the Debye–Waller factors (0.06Å2 for tetrahedral sites and 0.08Å2 for octahedral sites) and the diffusion constant (6.6 x 10-9m2/s at 673K) were obtained.

Hydrogen Diffusion in Magnesium Metal (α-Phase) Studied by ab initio Computer Simulations. H.G.Schimmel, G.J.Kearley, J.Huot, F.M.Mulder: Journal of Alloys and Compounds, 2005, 404-406, 235-7