The addition of two-body corrections in AC(2)-QM/MM greatly improves both geometry parameters and cohesive energies (see Figures ). While for vdW dominated systems like benzene the differences are negligible, they are severe for hydrogen bonded crystals. Cell volumes are always underestimated (MAD of 3.1%) compared to experimental values, but differences are much lower than at the AC(1)-QM/MM level. Among all systems, ammonia turns out to be a difficult case showing a much larger deviation of cell volume (13% smaller than experimental values) than the other systems (MAD of 2.6%). Similar issues are found in the periodic calculations using the same functional, thus the results for ammonia are deemed a systematic outlier.