The resonant Auger electron spectrum of core-excited ethylene: A combined experimental and theoretical investigation

We present measurements and calculations of the electronic decay of core-excited states in gas-phase ethylene. We have studied the decay of C 1s --> pi* core-to-valence resonances and the decay of the 1s --> 3s, 1s --> 3p, and 1s --> 4p Rydberg states. In addition, ab initio calculations are presented for the final states from the decay of the 1s --> pi* resonantly-excited state. The final states are calculated using configuration interaction wave functions for the intermediate (core-excited) state, and for the final state. The calculated spectrum compares well with the experimental spectrum and all final states may be identified. The method used for the calculation therefore seems very promising for other alkene molecules. (C) 1999 Elsevier Science B.V. All rights reserved.