AN AB-INITIO CALCULATION OF THE VIBRATIONAL STRUCTURE OF THE FIRST BAND OF THE PHOTOELECTRON-SPECTRUM OF CCL3

Making use of the coupled electron pair approximation (CEPA-1), two-dimensional potential energy functions have been calculated for the electronic ground states of CCl3 and CCl3+. Therefrom, vibrational term energies and wavefunctions were obtained variationally and were used to compute the rather complex vibrational structure of the first band of the photoelectron spectrum within the Franck-Condon approximation. The adiabatic ionization energy is calculated to be 7.990 eV which compares well with the experimental value of 8.109+/-0.005 eV.