Simulations of hydrogen diffusion were performed at 450 and 580K. Two key experimental observations were reproduced by the model: strong deviations from simple jump diffusion behavior and an anomalous Debye-Waller factor. The simulation revealed a rapid local-diffusion motion, confined mainly to the so-called 4T configuration. The time scale for this motion was found to be of the order of 100 to 200fs.

Rapid Local Diffusion of Hydrogen in Niobium Revealed by a Molecular-Dynamics Study. Wahnström, G., Li, Y.: Physical Review Letters, 1993, 71[7], 1031-4