The quantum aspects of H motion in Nb were elucidated using the path integral simulation technique. It was argued that the most important effect around 500K could be viewed as a temperature and isotope dependent shift of the potential energy surface, and that treating the dynamics of H motion classically at that temperature was reasonable. The purely classical isotope effect was also determined but the molecular dynamics simulation data did not exhibit the classical isotope effect for the pre-factor, due to the more complicated diffusion behavior at high temperatures.

Quantum Aspects of Hydrogen Motion in Niobium at High Temperatures. von Sydow, B., Wahnström, G., Li, Y.: Journal of Alloys and Compounds, 1995, 231[1-2], 214-9