From these results, a consistent picture emerges for the porous π-stacked systems. The vdW energy profile closely resembles the total interaction energy profile, even more so for the porous π-stacked dimers than for benzene dimer. As compared to the latter system, the larger (porous) dimers can relieve Pauli repulsion with a small parallel-displacement that leaves most atoms in close proximity, so that not too much favorable dispersion is lost. In sharp contrast to the conventional Hunter-Sanders (quadrupolar electrostatic) picture, electrostatics opposes (rather than drives) offset-stacking.