The conventional point of view in the organic chemistry literature is that π-π interactions are controlled by quadrupole-quadrupole interactions between the arene rings, recognizing that the benzene monomer has a rather large quadrupole moment for a small molecule. This results from the π-electron density on its faces that leads to electropositive C-H bonds, as depicted in Fig. . The offset-stacking phenomenon, whereby two proximal arenes are much more likely to be found in a parallel-displaced arrangement than in a face-to-face-configuration, 240,241 is also typically explained in terms of quadrupolar electrostatics. The argument is that quadrupole-quadrupole interactions are repulsive in the face-to-face configuration but attractive in the edge-to-face arrangement, which is certainly true according to multipolar electrostatics calculations (Fig. ) but misrepresents exact electrostatics.