where τ0 is the pre-exponential factor, Ueff is the energy barrier of Orbach processes, C and n For 1-Sm the total CF splitting was found to be 250 cm -1 with the majority composition of a 98.1%|±1/2⟩ indicating a weakly magnetic ground state. The pure ground state is consistent with the C3-symmetry inhibiting mixing with other states. The weakly magnetic ground state is consistent with the TIP observed in the χMT vs T plot. However, the magnetization data deviates from the calculated linear dependence, suggesting CASSCF underprediction of the |±5/2⟩ contribution to the ground state. The expected ground J = 0 for 1-Eu was found and consistent with TIP observed in the susceptibility and weakly magnetic ground state observed in the magnetization curves. For 1-Ho and 1-Er the total CF splitting of the ground J multiplets are 380 and 400 cm -1 respectively, with highly mixed ground states for 1-Ho, and 80.3%|±1/2⟩ for 1-Er.