For Tyr and Mms dimers, we also considered the effect of adding explicit waters in the calculations. In this case, we evaluate the interaction energy of the dimers with respect to the monomer composed of one ring hydrogen-bonded to a water molecule. Both Tyr-Tyr and Mms-Mms systems can interact through hydrogen bonds with these waters. Still, the interaction of mimosine rings is more efficient since it can act both as a hydrogen donor and acceptor through the alcohol and carbonyl oxygens at the same time. Interestingly, the interactions with water molecules stabilize the parallel orientation of the mimosine rings, obtaining the overall stronger interaction among dimers, -14.1 kcal/mol, since both water molecules can adopt a geometry in which they also interact through a hydrogen bond. Notice, however, that even in the case of the antiparallel Mms-Mms structure, the addition of water molecules also has a stabilizing effect, with interaction energy of -13.4 kcal/mol. The DE int in both Mms-Mms dimers is significantly higher than in Tyr-Tyr dimers.