Interference effects in Auger resonant Raman spectra of CO via selective vibrational excitations across the O 1s 86 2 80 resonance

The Auger resonant Raman spectra of CO, arising from the transitions to the X and A final electronic states of C O+, have been recorded at photon energies corresponding to the vibrational excitations v 80 b2=3,5, and 8 in the O 1s 86 2 80 resonance. The spectra are simulated within the model that takes into account both the lifetime-vibrational interference (LVI) and interference with the nonresonant photoemission. The spectroscopic parameters, 89e, f 89e xe, db and re, of the O 1 s 88 1 2 80 core-excited state, necessary for the simulation, have been derived by fitting the Franck-Condon simulation to the total ion yield spectrum, assuming a Morse potential for the O 1 s 88 1 2 80 state. Not only the LVI but also the interference with the nonresonant photoemission turn out to be significant.