A vibrationally resolved C 1s-1 auger spectrum of CO2

The high-resolution Auger spectrum of CO2 subsequent to C 1s(-1) photoionization is reported along with the corresponding photoelectron spectrum. Auger transitions to seven quasi-stable final states are observed. They are assigned on the basis of theoretical results in combination with the assumption that the Auger spectrum is dominated by transitions to singlet states. From the vibrational progressions in the Auger spectrum, the vibrational energies h omega, the anharmonicities xh omega and the equilibrium distances R-e for the dicationic final states are derived in a fit analysis assuming Morse potentials.