XPS of oxygen atoms on Ag(111) and Ag(110) surfaces: Accurate study with SAC/SAC‐CI combined with dipped adcluster model

O1s core‐electron binding energies (CEBE) of the atomic oxygens on different Ag surfaces were investigated by the symmetry adapted cluster‐configuration interaction (SAC‐CI) method combined with the dipped adcluster model, in which the electron exchange between bulk metal and adsorbate is taken into account properly. Electrophilic and nucleophilic oxygens (O_elec and O_nuc) that might be important for olefin epoxidation in a low‐oxygen coverage condition were focused here. We consider the O1s CEBE as a key property to distinguish the surface oxygen states, and series of calculation was carried out by the Hartree–Fock, Density functional theory, and SAC/SAC‐CI methods. The experimental information and our SAC/SAC‐CI results indicate that O_elec is the atomic oxygen adsorbed on the fcc site of Ag(111) and that O_nuc is the one on the reconstructed added‐row site of Ag(110) and that one‐ and two‐electron transfers occur, respectively, to the O_elec and O_nuc adclusters from the silver surface. © 2013 Wiley Periodicals, Inc.