Ab initio Density Functional Theory calculations are here reported to characterize the adsorption of methanethiol at the Cu (110) surface. Theoretical results suggest that the binding of the adsorbate to the substrate is rather weak and the molecular geometry is correspondingly almost unaffected by the adsorption. Otherwise, when C H 3 S H deprotonates producing methanethiolate, a stronger chemical bond is realized between the sulfur atom of C H 3 S radical and Cu surface atoms. A detailed study of structural and electronic properties of methanethiolate on Cu (110) for a p (2× 2) and a c (2× 2) overlayer structure has been carried out. We find that, in the most stable configuration, the molecule adsorbs in the shortbridge site. The chemical bond arises due to a strong hybridization among p orbitals of sulfur and d states from the substrate, as it is deduced by an analysis of partial densities of states and charge densities.
American Physical Society
31 May 2007
Volume: 75 Issue: 19 Pages: 195444
Physical Review B