Properties of the self-consistent field treatment of conjugated molecules

The polarizability properties of π electron systems are treated by the self-consistent field method, as modified by Pople for application to conjugated molecules. An analytical treatment of the π electron configuration of substituted hydrocarbons deduces certain universal symmetry properties of this method, and contains the Hückel treatment of inductive substituents as a simplified special case. Whereas the usual Hückel theory derives results by approximate perturbation methods, the treatment given here is formally exact. In a later section s.c.f. polarizability coefficients, as calculated on an Elliott 402 digital computer, are given for benzene, naphthalene, anthracene and phenanthrene, and the predictions of chemical properties are shown to be in better agreement with experiment than predictions derived from Hückel theory.