For the anion-molecule data set, MAEs with respect to CCSD(T)/CBS benchmarks are 3 kcal/mol when the def2-ma-TZVP basis set is used, although maximum errors are about 8.5 kcal/mol. Independent of basis set, the largest error is incurred for the very challenging Cl -(HCl) complex consisting of a proton that is shared equally between two Cl -ions, yet must be assigned to one monomer or the other for the purpose of (X)SAPT calculations. For the XSAPT + δHF + MBD calculations, this outlier is noticeably reduced by by additional diffuse functions so in that case there is a reason to prefer def2-ha-TZVP over def2-ma-TZVP, which is not surprising for a calculation involving an anion.