DFT calculations for 1-La were performed using ORCA v5.0. starting from the XRD structure. Reference chemical shielding was found from an optimized structure of H3PO4 using each method. In all cases scalar relativistic ZORA was employed alongside the GD3 dispersion correction and the def2-TZVP basis set 100 in its relativistically contracted form. The SARC form 101 of this basis set was used for La. The DFT methods used were BP86, 102,103 and B3LYP 104,105 with a range of exact exchange contributions. The PCM solvent model 106 was investigated, but was found to be ineffective (see Supporting Information Table ). NBO calculations used NBO 6.0 107 in Orca. They were carried out using the DFT methodology described above with B3LYPHF20 and B3LYPHF30.