Static polarizabilities of the Ne, Mg and Ar isoelectronic sequences

Numerical procedures are employed to determine uncoupled hartree-Fock polarizabilities α0 for members of the Ne, Mg and Ar isoelectronic sequences. For each system the first-order correction (α1) to the polarizability is evaluated and it is found that both α0 + α1 and the ‘geometric approximation’ α0/(1 - α1/α0) are generally in accord with polarizabilities determined from the fully coupled Hartree-Fock scheme. It is concluded that, as for smaller systems, this approach provides an economical means of obtaining a satisfactory approximation to the coupled Hartree-Fock polarizability of an atom.