The magnitude and trend of these numbers do not provide a clear understanding of the motif prediction for vdW-DF2. vdW-DF2, as compared to its predecessor vdW-DF1, changes the revPBE functional to the revised version of the PW86 functional . Indeed, when compared with revPBE+GD2, we see that vdW-DF2 does bind the amines more favorably across the board. Its magnitude is similar, though, to revPBE+GD3. GD3 accounts more generally for interaction energies, as well, so both methods could be correcting similarly for the interaction energies. More studies are needed on the performance of non-local functionals.