Effective-Field Calculation of Electronic Polarizability

Electronic multipolar polarizabilities of closed-shell isolated atomic systems are calculated by a variational method using, as trial functions, the perturbed wave functions given by the uncoupled Hartree-Fock method. The external field is replaced by an effective parametric field taking into account the coupling between the deformations of the various orbitals. Numerical results obtained for F^- and Cl^- show a much better agreement with the experimental data.