Ab-initio Simulation of Hydrogen Atom Interaction with Tungsten

The results of calculations of stable configurations of atomic hydrogen in the tungsten bulk, in the presence of vacancies, as well as on the surface (100) and in the near-surface layers are given. Activation barriers for interstitial diffusion, on-surface diffusion, trapping in a vacancy, detrapping from the vacancy, and transitions between on-surface and under-surface sites are calculated. Hydrogen-vacancy interaction is considered for the case of several H atoms trapped in a vacancy.