This is simply Eq. ( ) without the dispersion or exchange-dispersion terms, but where the name suggests that KS-DFT is used to compute the SCF monomer wavefunctions. The SAPT(KS) model in Eq. ( ) needs to be augmented with some form of dispersion, e.g., to obtain SAPT(KS) + D. It might or might not be augmented with a δHF correction, which will be indicated explicitly if so. Even for SAPT(KS), we will always use HF orbitals to evaluate δE HF because a supramolecular KS-DFT calculation mixes different energy components whereas δHF is intended as a correction for induction. Thus,