I've been teaching upper-level advanced inorganic and just wanted to alert the Shriver & Atkins users that the Tanabe-Sugano diagrams for the d² and d⁸ electronic configurations are incorrect. It's subtle, but a nuisance nonetheless.

The second problem with the d² (and the d⁸) TS diagram is the ¹E(¹D) state crosses the ¹T₂(¹D) state at strong ligand fields. (Look at the energies of the other ¹E_g and ¹T_2g terms arising from the ¹G free ion term. From configuration interaction considerations it is clear that these diagrams have a problem.)

I have attached correct TS diagrams for those using Shriver & Atkins with stated C/B ratios. For those of you that would like to make your own diagrams then the energies of the triplet states are as follows (for d⁸ change the sign of the Δ_o/B).

cheers,
Kevin