where E XSAPT,2B int,AB (A, B, . . . , N ) is the two-body XSAPT-EDA in Eq. ( ) applied to the dimer AB. The additional notation suggests that this quantity is a function of all N monomers, because the dimer SAPT calculations employ XPol monomer wavefunctions that are computed in the presence of embedding charges for the remaining N -2 monomers. As such, even the pairwise energies are many-body properties.