Vibrational excitation in C 1s and O 1s photoionization of CO

Abstract

The C 1s and O 1s photoelectron spectra of the CO molecule have been measured with high resolution. The vibrational spacing of the state is significantly lower than in the state and in the molecular ground state. Compared to the ground-state equilibrium C - O distance of 1.128 Å, we extract from the analysis of the Franck - Condon factors bond lengths of 1.079(2) Å and 1.167(4) Å for the C 1s and O 1s core-ionized states, respectively.