The problem of obtaining spectroscopic information from structureless electronic (luminescence or absorption) spectra of complex molecules is treated. Our previous model for the description of structureless spectral bands is extended to account for two (rather than one) optically active vibrations in the electronic tarnsition. In comparison with previous treatments more detailed data are obtained a bout the changes in the excited state geometry as well as the frequencies of zero-electronic transitions for a number of (substituted) phtalymids.