By contrast, the M-P-Si groups in the non-linear optimized structures were more symmetric (Figure , Table ). This suggests that the bent P-M-P bond angles are a consequence of the steric demands of the [P(Si i Pr3)2] -ligands. To fit these ligands around the metal, it is necessary to distort at either the metal centre or the P atoms, with the distortion at the metal being more favourable. The solid state structure of Cd[P(SiPh3)2]2 shows relatively symmetric Cd-P-Si angles (100.9(2)°, 98.2(1)°) and a linear P-Cd-P angle, suggesting that a smaller ligand removes the need for distortion. Geometry optimization (without restraints) of the less sterically demanding Cd[P(SiMe3)2]2, starting from linear and non-linear geometries, afforded both linear (P-Cd-P = 179.9°) and near-linear (P-Cd-P = 177.5°) molecules. These two geometries showed near-identical energies (ΔG = 0.1 kcal mol -1 ), suggesting that there is little energetic difference between these two coordination environments for the less sterically demanding [P(SiMe3)2] -ligand.