Distribution of aromatic and non-aromatic level-δ C atoms in χ
frames. (Color online) a) Distribution of aromatic and b) non-aromatic level-δ C atoms, in the stereographic projection of the unit two-sphere centered at the Cγ atom. In a) the (dark) blue is Cδ1 and (light) green is Cδ2. Some outliers have been encircled, as examples. The (black) circles around the center denote the average distance of the distribution.