The role of d electrons in ab initio chemisorption cluster model calculations. Atomic hydrogen on Cu(100) and Ag(100)

Abstract

The effect of d electrons on the chemisorption of atomic hydrogen on Cu 5 and Ag 5 cluster models simulating the (100) bulk surfaces is obtained through ab initio SCF calculations which use different sets of pseudopotentials. From a quantitative viewpoint the inclusion of the d electrons of the interacting cluster model atoms in the pseudopotential lead to a binding energy which is underestimated by about 10% (Cu 5H) and 15% (Ag 5H) with respect to the all valence electron treatment. On the other hand, a mixed pseudopotential approach is found to yield results in excellent agreement with the all valence electron calculations.