Oxygen-induced Rh 3d(5/2) surface core-level shifts on Rh(111) - art. no. 205415

High-resolution measurements are reported of the surface core-level shift ( SCLS) of the 3d level for the Rh(111) surface as a function of oxygen cover age Theta on the surface. These measurements are analyzed by density-functi onal theory calculations of the initial- and final-state contributions to t he shifts. The calculations are found to reproduce well the trends and magn itudes of the experimental shifts. Adsorption of oxygen shifts the Rh 3d su rface con levels to higher binding energies with the magnitude of the shift depending almost linearly on the coordination number of Rh surface atoms t o O adatoms. The Rh 3d binding energy increases by about 0.3 eV per bond to an O adatom. This correlation is robust with respect to differences betwee n initial- and transition-state theory calculations of the SCLS's. The resu lts are discussed in a simple physical picture.