EOM/Propagator Calculations of Vertical Ionization Potentials of Cyclopropane

The valence-shell 2E'、1E"、2A₁'、1A₂"、1E" and 1A₁' vertical ionozation potentials of cyclopropane have been calculated by means of the Koopmans theorem and the EOM/propagator method with 2ph-TDA and third-order approximation treatment. In calculation, we have used the C (9s5p/4s2p)、H(4s/2s) Dunning basis set and the last reported geometrical structure of cyclopropene. The calculated results are compared with experimental values. The 2E'、1E"、2A₁' IPs calculated through the third-order approximation treatment are in good agreement with experimental results. In the inner valance 1A₂"、1E', the 2ph-TDA treatment is better than the third-order approximation. The ordering obtained via the Koopmans' theorem corresponds with the results of experiment.