The near-edge X-ray absorption fine structure investigation of c(2x2)-(K+CO) on the Co{10(1)over-bar-0} surface

Theoretical studies of O 1s near-edge X-ray absorption fine structure of c( 2 x 2)-(K + CO) adsorption on Co{10 (1) over bar 0} surface have been perfo rmed by the multiple-scattering cluster method (MSC). The results show that the bond-length of the adsorbed CO molecule is longer than that of the one with no K by ca 0.1 Angstrom. The comparison between the calculated spectr a and the experimental data demonstrates that a new weak pi-like structure appears at the higher energy side of the original pi resonance. This struct ure comes from the combined interaction of the CO molecule with both the K atoms and the Co substrate. (C) 1999 Elsevier Science B.V. All rights reser ved.