For 1-Ce none of the pNMR shift calculations give a clear agreement with solution experimental data (see Supporting Information Tables S24, S27 and S30); as Ce(III) has the smallest magnetic moment of all Ln(III) ions in the periodic table it also has the smallest paramagnetic shifts, and hence approximations in our electronic structure method and our gas-phase structural models are insufficient to capture the subtleties of these data. Considering 1-Nd, both 1 H and Si solution pNMR results show discrepancies between the experimental values and the values predicted using the XRD or optimized M(THF)2 structures. For the 1 H resonances, calculations using the XRD structure (optimized structure) predict shifts of -6.4 and ca. -0.5 ppm (-2.3 and ca. -0.4 ppm) for the "in-plane"/group 1 and "out-of-plane"/group 2 signals, respectively, compared to the experimental values of 4.9 and -5.0 ppm, respectively.