THEORETICAL-ANALYSIS OF THERMALLY STABLE ADSORPTION FORMS OF OXYGEN ON SILVER

Theoretical analysis of the properties of oxygen in the surface layer of silver is performed in a cluster approximation. The oxygen molecule is placed in an octahedral cavity of the Ag-14 cubic cluster. The O-2 /Ag-14 system is optimized and structural parameters determined by the ab initio Hartree-Fock method. The energies are estimated by methods taking into account electron correlation in the Moller-Plesset and den sity functional theory approximations. For the three nonequivalent pos itions of O-2 in the Ag-14 cluster, it is shown that the molecular for ms of oxygen may be stabilized The calculations showed that the ground stare of the O-2/Ag-14 system is a triplet but the spin density is de localized over the silver atoms. Spin polarization leads to splitting of the 3 sigma(g)-level. The oxygen molecule has intermediate paramete rs between the superoxide O-2(1-) and peroxide O-2(2-) with the bond l ength R(O-O) 1.41 Angstrom.