Abstract: Using the five-parameters Morse potential theory about the interaction between an atom and the surface cluster(shortened form 5-MP),the H- Ru(1121) stepped surface adsorption system was studied. At the same time , the 2H- Ru(1121) system and the interaction between the surface adsorption states were researched by means of the extended LEPS potential theory. The theoretical data indicate that there are four kinds of different surface adsorption states that are 3-fold adsorption states. In the meantime, there are two kinds of inner adsorption states, which have direct diffused channels. The theoritical analysis proclaims that α state is the strong repulsion adsorption state which interacts deeply with the inner adsorption states, β state is the weak repulsion adsorption states and γ state is the surface adsorption states which doesn′t interplay with the inner adsorption states. The presumption that the α state has assigned to the 4-fold adsorption state by Fan et al. according to their experimental result doesn′t obtain the support of our theoretical data.

Key words: H-Ru(1121) system, Five-parameters Morse potential, Extended LEPS potential, Surface adsorption, Stepped surface