The determination of the local adsorption structure of SO2/Ni(111): multiple-scattering cluster studies

The multiple-scattering cluster (MSC) method has been used to calculate the sulphur Is near-edge x-ray absorption fine structure of SO2 adsorbed on Ni (lll). Our investigation confirm the flat-lying adsorption structure of SO2 /Ni(lll) and shows for the first time that the fee threefold hollow site is the most preferable adsorption site. It has been shown that the O-S intram olecular bond length is elongated by 0.07 Angstrom, the angle OSO bond angl e is reduced by 10 degrees after adsorption and the adsorption height is 2. 0 +/- 0.2 Angstrom. Furthermore, R-factor analysis exhibits a local minimum in the vicinity of the fee threefold hollow site, which is partly in agree ment with the experimental result.