The quantity E elst + E exch is often grouped together as "electrostatics plus finite size", or equivalently as the electrostatic interaction between antisymmetrized monomer wave functions. This is convenient because the sum of these two energy components is often more comparable in magnitude to the remaining energy components (E ind and E disp ), where electrostatics and exchange individually are often much larger in magnitude but opposite in sign, at least where equilibrium geometries are concerned. The average basis-set dependence of E elst + E exch is presented in Fig. . On the ∼ 1 kcal/mol energy scale it is clear that a triple-ζ basis set is required to obtain converged results, but that only minimal augmentation is needed in that case. The def2-SVP result is qualitatively wrong but even with a full complement of diffuse functions (i.e., def2-SVPD), the results are clearly inferior to def2-TZVP. Convergence is reached at def2ma-TZVP.