We have calculated the sulphur 1s near-edge x-ray absorption fine structure (NEXAFS) spectra of SO3 molecule and SO3 adsorbed on Cu(111) in terms of the multiple-scattering cluster (MSC) and DV-Xα methods. The cause of the resonances in the NEXAFS spectra has been revealed. MSC calculation shows that the SO3 molecule plane is distorted after being adsorbed on Cu(111) surface with C3v axis perpendicular to the surface. The S (SO3) atom is adsorbed on atop site while the three O (SO3) atoms located on the right in the vicinity of fcc hollow site. The adsorption height is 2.2 Å and the S-O bond length is 1.74 Å. These results are broadly in agreement with those of the x-ray standing waves analysis.
|Number of pages||9|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Jul 15 2002|