SEMIDIRECT ELECTRON PROPAGATOR CALCULATIONS ON CHLOROBENZENE IONIZATION ENERGIES

Electron propagator calculations on the lowest twelve vertical ionizat ion energies of chlorobenzene are performed with a semidirect algorith m. The OVGF and P3 approximations, where Feynman-Dyson amplitudes are equal to canonical molecular orbitals, were employed. The Cl p(pi) orb ital destabilizes the b(1) component of the e(1g) set of benzene to pr oduce the molecular orbital associated with the lowest ionization ener gy. Whereas the second highest occupied molecular orbital is nearly id entical to a component of the benzene e(1g) set, the corresponding ver tical ionization energy is larger than the lowest ionization energy of benzene. Holes corresponding to two higher final states have mostly C l 3p character. The remaining molecular orbitals strongly resemble the ir benzene counterparts, but significant Cl admixtures are present in most cases. Basis set comparisons indicate that the predicted order of final states is reliable. Up to 284 contracted functions are used.