Ligand field theory for actinides

The tendency of a 5f electron to drift from an actinide ion to the neighboring ligands is taken into account by introducing different radial functions for each 5f orbital. The approximation that this amounts to no more than a scaling of the wavefunction in the region of the actinide ion itself leads to a mere doubling in the number of crystal-field parameters. The theory is developed with particular reference to ions at sites of octahedral symmetry. The effective operators that produce equivalent results when acting between unmodified 5f-electron states are two-electron operators. Their irreducible parts, which possess specified group-theoretical properties, are defined and thus made available for more general analyses