Nuclear hexadecapole antishielding factors: tripositive lanthanide and tetrapositive actinide ions

Abstract

The nuclear hexadecapole antishielding factor η_∞ has been calculated using nonrelativistic Hartree-Fock-Slater wave functions and the Sternheimer uncoupled perturbation-numerical method for the tripositive lanthanide ions of Ce³⁺, Pr³⁺, Pm³⁺, Sm³⁺, Eu³⁺, Gd³⁺, Tb³⁺, Dy³⁺, Ho³⁺, Tm³⁺, Yb³⁺, and Lu³⁺, and the tetrapositive actinide ions of Th⁴⁺, Pa⁴⁺, U⁴⁺, Np⁴⁺, Pu⁴⁺, Am⁴⁺, Cm⁴⁺, Bk⁴⁺, Cf⁴⁺, Es⁴⁺, Md⁴⁺, No⁴⁺, and Lw⁴⁺. In all ions a more than 80% contribution to η_∞ comes from d→d radial perturbation corresponding to the outermost d orbital. The nonrelativistic |η_∞| values can be taken as 510±50 and 4000±1000 in the cases of tripositive lanthanide ions and tetrapositive actinide ions, respectively.