Fig. 11. Left: Silica-supported Y(iii) sites (a–c) and bulk yttrium oxide models (d–f). The depicted values represent the shielding along the three principal components of the respective shielding tensor. Colour code: σ₁₁ = red, σ₂₂ = green and σ₃₃ = blue. Right: DFT calculated solid state ⁸⁹Y NMR (g) of silica-supported Y(iii) sites (top) and bulk yttrium oxide models (bottom).15 The isotropic chemical shifts are depicted in red.