The nitrogen 1s near-edge X-ray absorption fine structure (NEXAFS) spectra of the N2O adsorbed on Ag(1 1 0) have been studied by the multiple-scattering cluster (MSC) and self-consistent field (SCF) DV-X alpha methods. Two adsorption models, in which the N2O molecule attached 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 N2O molecule is attached to the Ag substrate through the terminal nitrogen atom with the adsorption height h = 3.4 +/- 0.1 angstrom. In the overlayer the N2O arreange 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-X alpha method, which confirms the MSC calculations. (c) 2005 Elsevier B.V. All rights reserved.