Next, when the molecule relaxes from the vertically excited n,* state one can postulate that there will be a tug-of-war between the aromatic and the antiaromatic components. The first seeks to retain the (planar) S0 state geometry and the second strives to alleviate its antiaromaticity through geometric distortions (Figure ), i.e., to obtain a more bond length alternated and/or puckered structure. Thus, if the residual between the and -(anti)aromaticity components corresponds to some aromatic character, we postulate that the molecule will be more prone to retain a planar and/or bond length equalized structure in the n,* state, while it will pucker and/or become more bond length alternated if it has a residual with antiaromatic character. Yet, there can be factors that counteract these features, e.g., a preference of a particular heteroatom to have a more acute bond angle than the planar structure allows for. Hence, by jointly regarding the aromatic-antiaromatic character of the vertically excited n,* state, we probe the hypothesis that molecules with n,* states with aromatic residuals between the and -components distort less while those with antiaromatic residuals distort more. There are also various types of n,* states with different state symmetries as there are two * orbitals (the b1 and a2 orbitals, Figure ), which are degenerate in benzene. As the b1 * orbital has a lobe at the E atom while the a2 * orbital has a node there, it is apparent that the orbital energy gap and the energies of the two n,* states (E(n,*)) are affected differently by the electronegativity of atom E. This indicates that the n,* excitation energies of a certain heteroaromatic compounds will be affected by several features, where the extent of n,* state (anti)aromaticity is only one, others being the S0 state (anti)aromaticity and differences in electrostatic repulsion, exchange interaction, and strain within the molecule when going from S0 to the excited state. Thus, a correlation between the (anti)aromatic residual of an n,* state and the excitation energy is unlikely. Still, correlations may be observed within closely related compounds, e.g., among isomers or substituted derivatives of a specific heteroaromatic.