Multiple-scattering theoretical study on near-edge X-ray absorption spectra of C2H4/Ni(100)

The carbon K-edge near-edge X-ray absorption fine structure spectra of adsorption system C2H4/Ni(100) were calculated by multiple-scattering cluster method. By a comparison between the theoretical results and experimental spectra, the chemisorption geometries of this system were determined. The results show that the molecule is adsorbed on the perpendicular bridge site, and the distance between C atom and the nearest Ni atom is 1.70 Angstrom unit while the molecular plane tilting to the surface with 50°C. It is found that the interaction between H atom and Ni substrate plays an important role in the formation of adsorption structure. These results were verified by other ways.