The accuracy of SAPT0(KS) interaction energies depends critically on the use of asymptotically-correct exchange-correlation functionals. Long-range corrected (LRC) functionals offer a simple means to enforce this constraint but the range separation parameter must be tuned separately for each monomer, in order to obtain correct asymptotics. To this end, we use the LRC-ωPBE functional combined with the "global density-dependent" (GDD) tuning procedure. As compared to tuning based on the ionization energy criterion, GDD-tuned SAPT0(KS) and XSAPT + MBD results are essentially identical. 2.2. XSAPT. The XSAPT approach uses a selfconsistent charge embedding procedure based on the variational "explicit polarization" (XPol) formalism. In this approach, SCF wave functions for the monomers are computed in the presence of wave function-derived atomic point charges. For this purpose we use Charge Model 5 (CM5), whose efficient implementation for XSAPT calculations is described in Ref. 56. CM5 charges are based on the Hirshfeld atomic charge model procedure but introduce parameters in an effort to obtain more accurate dipole moments.