Foundations of conjugated circuit models
A Simpson-Herndon model Hamiltonian defined on a space of ortho- gonal Kekul; structures is derived for 1-factorable polyhex species (e.g. benzenoid hydrocarbons) from either of two antecedent models. One antecedent model is the semiempirical valence-bond model treated in the simple reso- nance-theoretic approach of Pauling and Wheland; the other is the Pariser- -Parr-Pople model treated within the bond-orbital resonance-theoretic ap- proach of ZivkoviE. Finally the conjugated-circuit scheme of Randit is ob- tained, though in a modified form.