For (annulene) 2 , similar two-dimensional contour plots of E int and E vdW are provided in Fig. . As compared to benzene dimer, the repulsive region extends to larger displacements, consistent with a larger offset: 2.5 Å in (annulene) 2 as compared to 1.8 Å in (benzene) 2 . A potential well of -13.1 kcal/mol appears at 3.2 Å displacement along the vertical direction, which is the displacement direction of the one-dimensional scans in Fig. , and another local minimum of -14.4 kcal/mol can be found at a displacement of 2.6 Å in an oblique direction. In this case, the vdW surface predicts local minima along similar radial directions but with an additional offset of ≈ 0.5 Å. These local minima in E vdW are much shallower (at -3.5 kcal/mol) than those in E int surface. These differences are ascribable to the more significant magnitude of E elst in the case of (annulene) 2 . For example, E elst = -22 kcal/mol at the coordinate origin in Fig. , and can also be understood as the difference between E int (Fig. ) and and E vdW (Fig. ). However, a twodimensional scan of E elst (Fig. ) does not reveal any local minima. Instead, E elst simply becomes less attractive in all directions emanating from the eclipsed-cofacial coordinate origin, again demonstrating that electrostatics opposes rather than drives offset-stacking. The only other energy component to exhibit any local minima is E ind (see Fig. ) but these minima have well depths of less than 1 kcal/mol.