The adsorption of H atoms on Ni(111) subsurface, Ni(211) and Ni(533) stepped surfaces was investigated by using the 5-parameter Morse potential (5-MP) of interaction between an adatom and a metal surface cluster. The adsorption sites, adsorption geometry, binding energy, and eigenvibrational frequencies of H—Ni systems were obtained. On the Ni(111) surface at low coverage, H atoms are adsorbed preferably on threefold hollow sites; with the coverage increasing, H atoms occupy the subsurface octahedral sites and tetrahedral sites. On the stepped surfaces Ni(211) and Ni(533), H atoms are adsorbed preferably on the fourfold hollow sites at low coverage; with the coverage increasing, the H atoms also occupy on the threefold hollow sites of the (111) terrace. The threefold sites near the fourfold sites are strongly affected by the height of the step and terrace. Moreover, the diffusion barriers of H atom were calculated to obtain the lowest energy pathway of diffusion on the surfaces.

Key words: H—Ni system, adsorption and vibration, subsurface, stepped surface