Q.In an octahedral crystal field, draw the figure to show splitting of d orbitals.

Step 1. Start from the five degenerate d orbitals of the free gaseous metal ion, all at one energy level.

Step 2. As the six octahedral ligands first form an imagined spherical field, ALL five orbitals rise together to a new, still-degenerate 'average energy' or barycentre level.

Step 3. As the ligands then take up their real, directional positions along the +x, -x, +y, -y, +z, -z axes, the orbitals split into two sets: dz² and dx²-y² (pointing directly at the ligands) rise further, by 3/5 Δ₀ ABOVE the barycentre, forming the eg level; dxy, dyz and dxz (pointing between the ligands) fall, by 2/5 Δ₀ BELOW the barycentre, forming the t2g level. …

Reproduce the three-stage octahedral splitting diagram from Section 5.6.2.1: free-ion degenerate level, raised barycentre level, then t …

• Splitting the orbitals directly from the free-ion level without showing the intermediate 'average energy in a spherical field' stage, which is needed to correctly anchor where +3/5 and -2/5 Δ₀ are measured FROM. …