Electronic Structure of a "Poisoned" Transition-Metal Surface

The authors report self-consistent linearized-augmented-plane-wave calculations of the electronic structure perburbations induced by a catalytic "poison," S, on a Rh(001) surface, focusing particularly on their distance dependence. The S-induced charge density vanishes beyond the immediately adjacent Rh atoms. However, the Fermi-level density of states, which is not screened, and which governs the ability of the surface to respond to the presence of other species, is substantially reduced by the S even at non-adjacent sites.