Potential energy curves of the quasi-stable states of CO2+ determined using Auger spectroscopy

Observations of Auger transitions to quasi-stable states of CO2+ subsequent to C 1s−1 and O 1s−1 ionizations of CO are presented along with the corresponding photoelectron spectra and calculations of the potential energy curves. The equilibrium distances Re, the vibrational energies ℏ ω, and the anharmoncities x ℏ ω, for the final states a1Σ+, b1Π, A3Σ+, and d1Σ+ are derived from fits to the spectra by assuming Morse potentials. A comparison of these Morse potentials with theoretical potential energy curves reveals excellent agreement in the Franck–Condon regions of the Auger transitions. The relative intensities for the observed C 1s−1 and O 1s−1 Auger transitions are also derived.