Adsorption model determination of N 2O/Ag(1 1 0) by theoretical studies of near-edge X-ray absorption fine structure

Abstract

The nitrogen 1s near-edge X-ray absorption fine structure (NEXAFS) spectra of the N 2O adsorbed on Ag(1 1 0) have been studied by the multiple-scattering cluster (MSC) and self-consistent field (SCF) DV-Xα methods. Two adsorption models, in which the N 2O molecule attached to the Ag substrate through the central nitrogen (N C) atom and the terminal nitrogen (N T) atom, respectively, have been checked up thoroughly. The MSC calculation and the R-factor analysis show that the N 2O molecule is attached to the Ag substrate through the terminal nitrogen atom with the adsorption height h = 3.4 ± 0.1 Å. In the overlayer the N 2O molecules arrange themselves into a tilted chain due to the interaction between the cations and the anions in the molecules. The physical cause of the resonances in the NEXAFS spectra mentioned above has been discussed by the DV-Xα method, which confirms the MSC calculations.