We employ the switching/Gaussian ("SwiG") discretization algorithm, which uses atomcentered Lebedev quadrature grids for each atomic sphere. Each surface point s i is assigned a Lebedev quadrature weight w Leb i and a switching amplitude F sw i with 0 ≤ F sw i ≤ 1, as shown in Fig. . The nature of the switching functions that is detailed elsewhere. The size of each discretization point s i in Fig. corresponds to the surface area a i that is assigned to that point, and which is the diagonal entry of the matrix A that was introduced in Section 2 .1. For a discretization point s i on the surface of atom B whose atomic radius is R vdW,B , we set