Light-induced excited spin-state trapping is used to change energies between sets of these entities via spin crossover. Exchange (10[1])energy is plotted against interatomic distance normalized (-5[1])to the size of one of these entities in Bethe–Slater curves. Unlike MLCT and LCMT bands, transitions between these entities (10[1])are weak (10[1])because they are (10[1])Laporte (-5[1])forbidden. (-5[1])These entities expand (-5[1])in the (10[1])nephelauxetic (“NEFF-uh-lox-ET-ic”) effect (10[1]-5[1])upon a decrease in the (10[1])Racah B parameter. (-5[1])The Jahn–Teller (-5[1])effect (10[1]-5[1])describes (10[1])degeneracy (10[2]-5[1])breaking (10[1])among (10[3])the e-sub-g (10[3])and t-sub-2g (10[1]-5[5])sets (10[1]-5[2])of (10[1])these entities (10[2])obtained (10[2])from crystal (10[1])field (10[1])theory. (-5[1])A torus around (-5[1])two lobes (-5[1])characterizes (10[1]-5[2])the (-5[1])z-squared (0[1]-5[4])type (10[1]-5[3])of these entities. (10[1]-5[5])For 10 points, (10[1]-5[1])name (-5[1])these entities, (10[1])partially filled (0[1]-5[1])in transition metals, (10[3]-5[1])whose energies (10[1])lie (10[1]-5[1])between (10[1]-5[1])their p and f counterparts. (10[6]0[1])■END■ (10[21]0[12])