Quadrupole Polarizabilities of Various Ions and the Alkali Atoms

Abstract

The quadrupole polarizability ${\alpha }_q$ which measures the induced quadrupole moment produced by an external field gradient has been calculated for three ions: ${\mathrm{Rb}}^{+}$, ${\mathrm{Cs}}^{+}$, and ${\mathrm{Bi}}^{5+}$, and for the neutral alkali atoms. The present calculations for ${\mathrm{Rb}}^{+}$ and ${\mathrm{Cs}}^{+}$, using the appropriate Hartree-Fock wave functions, represent a considerable improvement over our previous calculations, in which Hartree wave functions (without exchange) were employed. The values obtained for ${\alpha }_q$ of the alkali atoms are very large, ranging from 60.0 ${\mathrm{\AA }}^5$ for Li to 440.8 ${\mathrm{\AA }}^5$ for Cs. In Sec. III, we have collected the values of ${\alpha }_q$ for 11 ions, as obtained using the author's method of direct solution of the inhomogeneous wave equation. Wherever possible, these values have been compared to those obtained by other methods. The agreement is generally very good.