Here, we propose an efficient way to include vdW dispersion effects in ρ(r) from a (semi-local) DFA. This can be accomplished by using the Many-Body Dispersion (MBD) model, which has been successfully applied to describe anisotropic molecular polarizabilities , polarization response of atoms and molecules to electric fields , optical excitonic spectra , and to accurately capture effects of polarization and vdW dispersion in (bio)molecules and materials . We use the newly developed Fully-Coupled and Optimally-Tuned version of MBD (FCO-MBD) and validate this FIG. (a) Correlation plot of dispersion energy magnitudes as computed by SAPT versus FCO-MBD and MBD@rsSCS methods for the S12L dataset . The SAPT dispersion energy is defined as