The factor w should be carefully defined so that d/e ratio of sobEDAw will be close to that of SAPT as much as possible for wide variety of intermolecular interactions. The famous S66 is a well-balanced set of small molecule dimers containing C, H, N, O elements, the 66 dimers in the set spans d/e ratio from very small to very large (0.29 to 5.42); in other words, this set involves interactions from highly electrostaticsdominated to highly dispersion-dominated. The d/e ratios in S66 paper were calculated using DFT-SAPT method at PBE0AC/aug-cc-pVDZ level with empirical enhancement for dispersion component, they provide a very useful reference of determining the way of evaluating w parameter. We performed sobEDA for the S66 set at B3LYP-D3(BJ)/aug-cc-pVTZ level, then we plotted scatter map between d/e ratios of DFT-SAPT and ∆Edc/∆Eels of sobEDA, as well as between d/e ratios of DFT-SAPT and (∆Edc+∆EDFTc)/∆Eels, see Figs. ) and 2(b), respectively. It can be seen that ∆Edc/∆Eels is consistently too small compared to d/e ratios of DFT-SAPT, while (∆Edc+∆EDFTc)/∆Eels is relatively too large in most range. However, as shown in Fig. found an ideal form of w function for realizing this purpose: