Shape resonances in vibrational excitation of molecules : [100] symmetric stretch mode excitation in CO2

Abstract

The differential cross-section for vibrational excitation of the [100] symmetric stretch mode in CO2 is obtained in the 1-35 eV energy range. Besides the well known πu shape resonance at 3.8 eV, two new resonance structures with low intensities and large widths are observed. These structures centred at 10.8 and 30 eV are attributed to σg and σu shape resonances respectively, as predicted by theoretical continuum multiple-scattering calculations by Dehmer and Dill