Uncoupled Hartree-Fock perturbation theory for the density matrix: the second-order properties of conjugated molecules

Abstract

The Hartree-Fock perturbative approach to second-order properties is developed in terms of the uncoupled first-order density matrix. Apart from its theoretical interest, the present formulation is particularly suitable for computational purposes. The applications are to π-electron systems: a comparison with coupled results for dipole polarizabilities, magnetic susceptibilities and shielding is also given.