On the use of symmetry in first-order perturbed HF theory. II

A method is described whereby molecular symmetry is employed to reduce the number of two-electron integrals in perturbed Hartree-Fock calculations of second-order properties. The method is a generalization of the Dacre-Elder procedure. First- and second-rank perturbing tensor operators are examined in the coupled HF approach to electric dipole polarizabilities, magnetic susceptibilities, quadrupole polarizabilities, and spin-dopolar contributions to spin-spin coupling constants. The procedure sketched here permits a large saving of computer efforts, which is shown by some illustrative examples