Information Table ). For the Si "in-plane"/group 1 resonances (group 2 not observed; now considering only 𝛿 vdH-S para ), the predicted shift using the XRD structure (optimized structure) is -22.3 ppm (-11.7 ppm), which varies from the experimental value of 6.3 ppm. When one THF ligand is removed the shift increases to 8.7 ppm, and then to 8.0 ppm when the second THF ligand is removed (see Supporting Information Table ). Hence, both the 1 H and Si pNMR data suggest a formulation of either Nd(THF)1 or Nd(THF)0 for 1-Nd in solution. All chemical shifts show pronounced discrepancy compared to experiment for the second averaging option (see Supporting Information Table ), whilst the third averaging option (see Supporting Information Table ) is also compatible with Nd(THF)1;