Multiple-Scattering Approaches to Near-Edge X-Ray Absorption Fine Structure of N₂O/Cu(100)

The nitrogen 1s near-edge x-ray absorption fine structure (NEXAFS) spectra of the N₂O adsorbed on the Cu(100) surface have been studied by multiple-scattering cluster (MSC) and self-consistent field DV-X_αmethods. It is shown that the N₂O molecule is adsorbed on the hollow site with the adsorption height h = 3.0±0.1A. The MSC calculation confirmed by a DV-X_α analysis has revealed the physical cause of the weak feature in the NEXAFS spectra mentioned above, which originates from the 1s core electrons of the centre and terminal nitrogen atoms transiting into the unoccupied σ^* orbital of the N₂O molecule.