Use of semiempirical models for calculation of B terms in MCD spectra. II. The Pariser-Parr-Pople (PPP) model: A consequence of the pairing symmetry in π systems with alternant skeletons

Within the PPP model, MCD spectra of two π-electron species which are paired in the sense of alternant symmetry are mirror images of each other. Consequences of this theorem for the understanding of MCD spectra of substituted alternant hydrocarbons are pointed out.