EasySpin to model the data (Figure ; see Supporting Information Table for full details of simulations). Attempts were made to collect spectra of 1-Sm but the results were not reproducible, consistent with decomposition occurring upon sample grinding. The spectra are highly axial, with gz values of 3.598 (1-Ce) and 5.969 (1-Nd), indicating that ground states are dominated by the highest mJ component of the ground J multiplet; these are very close to those predicted by CASSCF-SO calculations (3.498 and 5.874, respectively, Tables and).