THEORETICAL INVESTIGATION OF ETHYLENE ADSORBED ON NI(100) SURFACE BY THE MULTIPLE-SCATTERING CLUSTER METHOD

In this paper the carbon K-edge near edge X-ray absorption fine struct ure spectra (NEXAFS) of adsorption system C2H4/Ni(100) are calculated using the multiple-scattering cluster method. By a comparison between the theoretical results and experimental spectra, the chemisorption ge ometry of this system has been determined. The result shows that the m olecule is adsorbed on the perpendicular bridge site, and the distance between the C atom and the nearest Ni atom is 1.70 angstrom, while th e molecular plane tilting to the surface is 50-degrees. It is found th at the interaction between hydrogen atom and Ni substrate plays an imp ortant role in the formation of the adsorption structure. The above re sults are supported by other evidences.