Nuclear motion effects in the photoionisation of CO2

Abstract
A calculation of the photoionisation cross section of CO2 reveals that the sigma u shape resonance at approximately 19 eV, accessed by the 1 pi g and 4 sigma g valence levels, is reduced and broadened by coupling to the ground-state vibrational motion. Off resonance the effect of nuclear motion is negligible. Results are compared with experimental branching ratios.