Geometrical effect on the issue of asymmetric C 1s photoelectron angular distributions detected in coincidence with the fragment ion pairs of CO+–O+ for CO2 molecules

Abstract

We have measured C 1s photoelectron angular distributions (PADs) in coincidence with the CO+–O+ fragment ion pairs of CO2 molecules at the photoelectron energies of 85, 120 and 150 eV. The observed left–right asymmetric PADs have been well reproduced by our theoretical model taking into account the two degenerate zero-point bending vibrations. This leads to a conclusive result on the interpretation of such PADs; although it has been believed so far that they are the molecular frame, in fact they are the recoil frame.