Chemisorption of Atomic Hydrogen on Large-Nickel-Cluster Surfaces

First-principles Hartree--Fock calculations are reported for binding of atom at high-symmetry sites of low-index faces of Ni surfaces (using an Ni sub 20 cluster as a model). Chemisorption energies increase with ligancy the binding site, with bond energies of 1.6, 2.8, 3.2 and 3.0 eV for one-, two-, three- and fourfold sites, respectively. A reverse trend is found for omega sub e with values of 275, 170, 150 and 73 meV for ligancies of 1, 2, 3 and 4, respectively.15 refs.--AA