The binding energy of H in a (100) Nb slab was investigated via molecular dynamics simulations. A H-Nb interaction potential was introduced which comprised an attractive as well as a repulsive part and which was valid for surface diffusion calculations. Simulations were performed at high and low temperatures, with respect to the Debye temperature. In the former case, the H diffused in the slab according to a diffusion coefficient which was in agreement with experiment. In most cases, it was trapped within the slab at temperatures below 900K. There was an enhancement of the H binding energy, close to room temperature, and this led to self-trapping close to the surface.

Subsurface Bonding of Hydrogen in Niobium: a Molecular-Dynamics Study. A.H.Romero, I.K.Schuller, R.Ramirez: Physical Review B, 1998, 58[23], 15904-8