Near-edge x-ray-absorption fine-structure spectra from K-shell excitation of ${\mathrm{N}}_2$ molecules adsorbed on an Fe(111) surface (γ state) exhibit structures which, by comparison with corresponding gas-phase data, are identified as Rydberg and ${\pi }^{\mathrm{*}}$ multiple-electron excitations. These may obviously survive in the adsorbed state because of very weak valence-orbital interactions and large internuclear separations (approximately 2.5 Å) between the adsorbate and the substrate. Due to the oriented character of the molecules on the surface, the full angular dependence of these excitations is measured for the first time.

• Received 30 May 1989

DOI:https://doi.org/10.1103/PhysRevB.40.6409