Electronic states of C2H4++from double charge transfer spectroscopy and from SCF-CI calculations

Double ionization potentials of the ethylene molecule corresponding to the formation of the ground state and lower-lying excited states of C2H4 ++ have been measured by means of double charge transfer spectroscopy. The experimental results are compared with the results of accurate SCF-CI calculations on C2H4 ++. Very good agreement between the experimental and theoretical double ionization potentials is obtained enabling a full interpretation of the double charge transfer spectrum of C2H4 to be given.