but the grafting procedure spoils this relationship between energy and potential, leading to "stray" potentials that cannot be derived from any energy functional. Nevertheless, the grafting procedure is still used in the SAPT(DFT) approach, in which frequency-dependent density susceptibilities for the monomers, computed from KS-DFT calculations, are used to replace second-order dispersion in the SAPT0 energy formula [Eq. ( )].