Substitution effects by SCF and H�ckel theory

Abstract

A basic ansatz for the dipole moment has been programmed in Hückel theory and used to calculate some field-dependent properties. This is related to fundamental properties of shaped potentials rather than a good representation of real molecular properties. Limiting values may be meaningful and have been compared with semiempirical and SCF calculations. Coulson and Longuett-Higgins-style Coulomb integral perturbations were calculated. These give clear molecular design indications which are partially backed up by small-scale SCF calculations, using perturbations of the nuclear charge. This work is not intended to be comparable to good ab initio calculations but to point to rough and ready geometrical models of electrical susceptibility. © 1997 John Wiley & Sons, Inc.