“…Similarly to NICS(1) and NICS(1) zz , these plots show mainly shielding effects associated with the π electrons. The
contour plots in planes parallel to and 1 Å above the molecular planes of polycyclic aromatic hydrocarbons (PAHs) have been shown
[14,35] to capture the essence of the popular Clar aromatic sextets with high accuracy, providing visual and yet quantitative vindication of Clar's ideas. It should be noted that, at positions in the plane parallel to and 1 Å above the molecular plane different from that used to calculate NICS(1), at least two of the components
,
,
and
are non‐zero which makes the use of the zz components of the shielding tensor and its diamagnetic and paramagnetic contributions calculated in that plane less well‐justified than the use of the respective quantities calculated in the molecular plane.…”