This study establishes that pulsed EPR and paramagnetic solid-state NMR spectroscopies are highly complementary and able, when coupled with the advanced computational methods, to provide detailed information about the geometry and electronic structure of paramagnetic compounds such as Yb[CH(SiMe 3 ) 2 ] 3 . Besides the specific geometry typically accessible by X-Ray diffraction, this study provides direct spectroscopic evidences for the 3c-2e Yb-Me-Si interaction and for the presence of π-character in the Yb-C bond in this paramagnetic compound, paralleling what is observed for the diamagnetic Lu analog10 and so commonly among the corresponding d 0 organometallics, often referred to as an α-H agostic interaction. In fact, the magnetic data for Yb[CH(SiMe 3 ) 2 ] 3 indicates a f 13 ground state configuration with no evidence for a multiconfigurational ground state that is often observed in lanthanide compounds, probably further explaining the observed similarities with the Lu isostructural compound. Yet, while magnetic susceptibility measurements indicate that the magnetic moment is consistent with that of a free Yb(III) ion, CAS-based calculations instead reveal an unusually large crystal-field splitting resulting in a ground KD that is almost completely thermally isolated even at room temperature and which results in a large magnetic anisotropy.