We can now move on and focus on our B3LYP/def2-TZVP results. Excluding interaction 1, for which SARS-CoV exhibits the largest interaction energy (1-SARS-b), 2019-nCoV indeed seems to be capable of participating in stronger noncovalent interactions (2-nCoV, 3-nCoV-b, and 4-nCoV correspond to the strongest interactions for n=2-4). As somewhat briefly addressed by Morse et. al., most energetic "gains" associated with 2019-nCoV residues may be rationalized using chemical intuition. For instance, in interactions 2 and 4, 2019-nCoV clearly relies on hydrogen bonding while SARS-CoV is only capable of participating in either van der Waals (vdW), or sulfur-containing hydrogen bonding interactions -both can be expected to be weaker. In addition, 2019-nCoV apparently benefits from S-π stabilization in interaction 2, which can clearly turn significant in an appropriate spatial organization An important thing to here, however, is that the largest calculated energies for interactions n=1-4 should not, on their own, be simply considered as a measure for the overall interaction strength between SARS-CoV/2019-nCoV and ACE2. As mentioned in the introduction, such macro-scaled protein-protein interactions are driven by a great many noncovalent binding factors, and are characterized with significant conformational flexibility.