Application of molecular symmetry in near-edge x-ray-absorption spectroscopy of adsorbed species

Abstract

The importance of symmetry and selection rules in the near-edge x-ray-absorption spectra of adsorbed molecules is discussed. We show how the number of allowed resonances, their degeneracy, and polarization dependence can be predicted by reference to the appropriate molecular orbital scheme. Further, the effects of symmetry lowering, due to the presence of the surface, and of symmetry breaking, due to the creation of the core hole, may need to be considered. Recent data for the formate species adsorbed on a Cu{110} are used to illustrate some of these points.