above with the 4f-only active space, we observe only small changes in the calculated shifts (Table ). This clearly indicates that while the 4f-only active space is sufficient to effectively approximate the localized magnetic anisotropy of the metal ion, it fails to model the electronic structure of the ligands well enough to accurately describe the contact shift or the effect of the spatial distribution of the unpaired electron density on the pseudocontact shift. The former of these issues is expected to be more significant for the P nuclei, which are directly bonded to the Ln ions.