Predictions of medium-sized structures provide a straightforward test of size transferability. There are additional, albeit typically small, higher-order contributions in larger structures. Also, the n-body cutoffs are now in effect to reduce the number of computations. Table shows energies and forces of hexadecamers (16mers) from the literature computed with RI-MP2/def2-TZVP and compared against mbGDML, mbGAP, and mbSchNet results. The truncated MBE contributes a few kcal/mol errors depending on the system. For example, the MBE prediction of (H 2 O) 16 results in a 3.3 kcal/mol error whereas (MeCN) 16 has only a 0.2 kcal/mol error. Missing higher-order contributions or basis set errors are the most likely causes. All mbML models performed similarly well with (H 2 O) 16 . Most errors originated from