The CHB6 data set consists of M + (C 6 H 6 ) and M + (H 2 O) complexes for alkali metal cations: M = Li, Na, and K. As compared to the anions, XSAPT + δHF + ai D3 calculations result in smaller errors for these cationic complexes, with MAEs below 2 kcal/mol and maximum errors < 4 kcal/mol. However, the MBD model affords excessively large dispersion energies for the two complexes involving K + , e.g., E MBD+esDQ disp = -84 kcal/mol for K + (C 6 H 6 ), as compared to E aiD3 disp = -4 kcal/mol for the same complex. These very large dispersion energies manifest as significant overbinding of the K + complexes by XSAPT + δHF + MBD, with errors of 23 kcal/mol for K + (H 2 O) and 80 kcal/mol for K + (C 6 H 6 ), using def2-ma-TZVP. As such, these two complexes have been removed from the error statistics in Table in order to provide a more representative perspective or the other cation-molecule dimers. Even so, errors remain considerably larger than they are for XSAPT + δHF + ai D3 applied to the CHB6 data set.