Interaction of the atoms (H, S, O, C) with the Cu(111) surface

A density functional approach has been applied to study the interaction of the atoms (i.e. H, S, O, and C atoms) with two different cluster models of the Cu(111) surface, and either considering or neglecting the reconstruction of the surface. It is found that H atom forms essentially a covalent bond with the surface, while S, O, and C atoms form largely an ionic bond. Optimized results indicate that H, S, O, and C adsorbates prefer the high-coordination three-fold hollow site, the hcp site, at the Cu(111) surface. The adsorption energies of these adatoms on the Cu(111) surface are in the order of C > 0 > S > H. We also attempt to discuss the correlation between the properties of the adatoms and their adsorption characteristics on the Cu(111) surface. It can be concluded that the atomic valence and the electronegativity may better be used together to elucidate the difference in the adsorption energy between different adatoms for a given metal surface, and the atomic valence plays a more important role in such correlation. Our first-principle calculations agree well with the experimental reports. (C) 2002 Elsevier Science B.V. All rights reserved.