“…Although scarce, some solid-state materials containing Tb 4+ have been investigated through EPR and yielded a diverse range of g values. ,− In these cases, the g values in different host lattices span 1.997(5)–2.0146(4). The highest values were obtained in ThO 2 and ThSiO 4 host lattices, where g = 2.0146(4) and 2.011(5), respectively. , Similarly, g values for Eu 2+ and closely related Gd 3+ complexes exhibit a reduced g value compared to g e . ,,, A qualitative comparison between the values among materials containing Eu 2+ , Gd 3+ , or Tb 4+ is available only in pairs (e.g., Eu 2+ /Gd 3+ or Gd 3+ /Tb 4+ in related hosts/sites). The lack of close structural similarity, combined with a dependence on the local structure, makes it difficult to definitively determine the effect of the metal identity and highlights the importance of the close structural congeners in this work.…”