By jointly considering the investigated mono-and diheteroaromatics, one can conclude that as a rule-of-thumb a molecule with a high MCI( 3 n,*)tot is likely to have its first n,* state below the lowest 3 * state (Figure ), although the correlation is weak (R 2 = 0.42). Yet, the energy difference between the 3 n,* and 3 * states should depend on both the (anti)aromatic character of the 3 n,* state and the destabilizing antiaromatic character of the the n and lowest * orbital as compared to the highest  and lowest * orbital is larger for pyrazine than for pyridine (the orbital energy differences are 8.29 and 8.83 eV for pyrazine and 9.08 and 9.11 eV for pyridine, respectively, Table ). Yet, there is also a clear effect by the (anti)aromatic character of the 3 n,* state because for 9 and monosubstituted pyrazines there is a clear correlation (R 2 = 0.84, Figure ) between the E( 3 ,* -3 n,*) and MCI( 3 n,*), and there is a corresponding correlation between E( 3 ,* -3 n,*) and NICS( 3 n,*) although weaker (R 2 = 0.58, Figure ). Hence, the lowest 3 n,* states of the species which have these states as their T1 states are more aromatic than in the species which have these states as higher excited states (Tables ). Most monosubstituted pyrazines have T1 states of 3 n,* character (Figure ), yet, the -donating amino substituent leads to a pyrazine with the 3 * state as T1. However, as stated above, to only use the (anti)aromatic character of the 3 n,* state is an approximation because also the antiaromatic character and energy of the 3 ,* state is influenced by substituents. We also considered 9 and the monosubstituted pyrazines when analyzing the hypothesis on a correlation between the vertical E( n,*) and MCI(S0 -3 n,*). However, in this case there is no correlation (Figure ), and one reason can be partial delocalization of the excitation onto the substituent similar as found earlier for the 3 ,* state of substituted benzenes (vide supra). Still, the amino substituent leads to a pyrazine with high E( 3 n,*) while the silyl group does the opposite. We also explored this for 9 at distorted structures with relative energies at most 10 kcal/mol above the optimum, and also in this case we find no correlation (R 2 = 0.05, Figure ), likely due to a more significant loss of aromaticity in T1 upon distortion than in S0 (see SI, section 3.9).