For 1-Ce and 1-Nd, CASSCF-SO calculations (Tables S10-S13; note there are two non-equivalent molecules in the XRD structure of 1-Ce) give effective g-values for the lowest Kramers doublets as gx,y,z = 2.1, 3.0, 0.7 and 2.2, 2.4, 1.1, respectively, with the numerically smallest value (gz) corresponding to the orientation of the pseudo-C3 axis (Figure ); the anisotropy patterns agree with the experiments. For 1-Sm, CASSCF-SO calculations give gx,y,z = 0.4, 0.4, 0.6 for the lowest Kramers doublet. This has the opposite sense of anisotropy (gx,y < gz) to the experimental data (gx,y > gz), but given the numerically similar and very low (all < 1) effective g-values, such a switch in anisotropy will be very sensitive to subtle state mixing effects. Nevertheless, given the axially symmetric form of the EPR spectrum, gz must be associated with the pseudo-C3 axis.