For nonequivalent p-s and p-p term counting, the closed shell has . For , the open orbitals give and , henceHund's rules predict the order .
For , the electrons are in nonequivalent orbitals. All and combinations are allowed:Applying maximum spin first, maximum orbital angular momentum next, and smallest first for these less-than-half-filled open subshells gives the qualitative orderingThe state counts are for and for . Imposing the equivalent- restrictions would incorrectly discard allowed terms. These are Hund-rule predictions; exact interleavings in a real excited configuration require the actual Coulomb and spin-orbit matrix elements.