For AMBER-GAFF2, dimers with high electrostatic contributions result in larger errors (see Fig. of the SI) pointing to a limitation of partial charges. Contrarily, for GFN2-xTB, the higher errors appear to be associated with the local chemical environment. For example, the presence of P (in all 2Ix dimers), S (in all SF3Ix dimers) or Cl atoms (in both Folded F1I1, F1I3