On Perturbation Calculations for the  -Electrons and their Application to Bond Length Reconsiderations in Aromatic Hydrocarbons

An alternative method for calculating the atom-atom, atom-bond, bond-bond and other polarizabilities in π-electron molecules, originally due to R. D. Brown, is extended to deal with orbital degeneracy. It is then applied to a new discussion of the bond lengths in certain aromatic hydrocarbons. A simple and partly self-consistent method of calculation is developed, which yields results in satisfactory agreement with recent accurate experimental measurements.