A method is developed to include polarization effects in low-energy scattering of electrons from atoms, within the Hartree-Fock formalism. This description is different from the usual expansion in terms of the eigenfunctions of the atom. The method associates with each atomic orbital perturbed or polarized parts which also depend parametrically on the coordinates of the scattered particle. When the orbital function of the scattered particle is appropriately antisymmetrized with the total atomic function, augmented in this manner, a set of equations result which, in addition to the no-polarization terms, contain terms coming from the polarized orbitals. By virtue of the antisymmetry, these terms are of two kinds: direct and exchange. The direct terms lead asymptotically to the classical type of polarizability correction which was used by Bates and Massey. The exchange terms constitute a specifically quantum mechanical correction. This method is applied, in a certain approximation, to the $s$-wave scattering of electrons from oxygen. Only the most important kind of polarized orbital is taken into account. Within this approximation the exchange polarized terms make a contribution of approximately 15% to the cross section.

• Received 16 October 1956

DOI:https://doi.org/10.1103/PhysRev.107.1004