The study of Ni_nH(n=1-6) clusters by density functional theory

In this paper, the geometric structures and local relative stability of Ni_nH(n = 1-6) have been systematically calculated using the generalized gradient approximation (GGA) under density functional theory. The studied results indicate that adding an H atom to the Ni_n clusters does not significantly change the basic structures of Ni_n, and the most stable structures can be received by adsorbing an H atom on the side of pure Ni_n clusters. The binding energy of each atom of Ni_n and Ni_nH show same variation trend, the values of Ni_nH are larger than that of Ni_n. The fragmentation energy, adsorption energy and HOMO-LUMO gaps don't show obvious oscillation behavior with cluster size evolution, but the values are larger at Ni₆H, which illustrate that the corresponding cluster has high stability and low chemical activity. (paper)