For 2T-N (Fig. ), upon increasing the electron-withdrawing nature of the central N atom (i.e., for more negative ε py N ) the dark S 1 state moves to the red. Similarly, the highest energy excitation redshifts, while the band at intermediate energy, ascribed to S 2 , a doubly degenerate E ′ state, is marginally affected by ε py N . For 2T-N, acceptable agreement with experiment is observed in the region -13 eV < ε py N < -11 eV. Quite interestingly, Fig. shows that in this region (highlighted in orange) the ST gap is consistently negative.