What I don't understand: Golding & Halton employ their model Hamiltonian in an entire LS term. States with same MS and different ML have different f-orbitals occupied. Likewise when switching the Ln(III) ion. Why should different f-orbital occupations lead to the same ligand spin density? (2/2)

Thanks for the answers!
What I am mainly confused about: the primary origin of spin density is the partial occupation of the 4f orbitals. Common wisdom is that they polarize the more diffuse metal-centered orbitals that participate in weak covalent bonding with the ligands. (1/2)

My questions are:
1) How exactly does the constant A relate to the microscopic quantum-chemical Hamiltonian and its eigenstates?
2) Why should A be similar for isostructural complexes containing different lanthanide(III) ions?

The most innovative aspect of the implementation is the treatment of dipolar spin–spin coupling in a basis of configuration state function with a GUGA-like approach. I am happy to chat about this topic while still at #WATOC2025!