In addition, MMFF94 geometry optimizations and energy calculations were performed using the Avogadro software (Macintosh version 1.2). The sixteen geometries considered in this work were obtained in the following manner: first, four amino-acid dimers, corresponding to the noncovalent interactions between SARS-CoV and ACE2 addressed by Morse et. al. (see introduction), were directly extracted from the crystal structure considered in Ref. [PDB ID: 2AJF]. These dimers were then spatially reorganized (based on chemical intuition and bearing in mind that the polypeptide backbone must remain intact) to represent significant binding interactions, and subsequently optimized using the MMFF94 force-field to produce five additional structures. Finally, substitutions associated with 2019-nCoV were performed and reorganized-optimized in a similar mannerresulting in seven more structures (sixteen in total). For the sake of consistency, we have chosen to carry out MMFF94 geometry optimizations on the original, crystal-structurederived dimers -despite the fact no noticeable structural changes have seemed to result from such choice. All final geometries used in our interaction energy calculations are provided in .xyz format in the electronic supporting information.