STUDY OF FRANCK-CONDON ENVELOPES OF THE PHOTOELECTRON BANDS OF POLYCYCLIC AROMATIC-HYDROCARBONS

Franck-Condon envelopes of photoelectron bands of polycyclic aromatics are studied on the basis of MO and normal coordinate calculations. A simple ap This indicates that the present approach holds promise for predicting geometries of ionized molecules as well as vibrational envelopes of PE spectra. T The vibrational bandshapes and the geometry changes on ionization are discussed in connection with the types of normal modes and molecular orbitals. Ba Molecular deformations on ionization for a particular type of PE band are found to be distinct from those for the other types; for the Kekulé-bands t the short-axis bands and the long-axis bands ionized molecules are expanded preferentially along the corresponding molecular axis, and for the M-bands. © 1979.