Transferability of core potentials to f and d states of lanthanide and actinide ions

Abstract

An analysis is made of the transferability of frozen core potentials of neutral lanthanide and actinide elements to 4f/5f and 5d/6d states of their respective 3+ and 4+ ions. A good description of the orbital spin—orbit coupling constants ζ_4f/ζ_5f and ζ_5d/ζ_6d of the Ln³⁺/An⁴⁺ ions and of the 4f → 5d/5f ζ 6d transition energies is achieved by using [Kr]/[Xe, 4f] cores. The corresponding relativistic core ab initio model potentials (AIMPs) based on Cowan—Griffin atomic calculations, together with optimized Gaussian valence basis sets, are produced for the lanthanide elements Ce to Lu and for the actinide elements Th to Lr. Results are given for the Ce³⁺ and Pa⁴⁺ free ions and in Ce³⁺-and Pr³⁺-doped Cs₂NaYCl₆ and Pa⁴⁺-and U⁴⁺-doped Cs₂ZrCl₆ materials.