The aromatic rings of Phe and Tyr show evenly distributed negative charges among the carbons and positive among the hydrogens bonded to them. Whereas carbons bonded to the b carbon or electron withdrawing groups show more positive charges. This effect is also observed for Mms, but to a greater extent, with the carbons bonded to the hydroxy and oxo groups positively charged, especially the latter one. Furthermore, the N2 nitrogen atom of the Mms ring shows a more positive charge than those of its analogue carbons in Phe and Tyr, which can be correlated to the nitrogen donating two p-electrons by resonance, rather than the one donated by the carbons. These positive charges are balanced by the neighboring atoms, leading to significantly more negative charges in the CD and CE atoms. While these distinctions for the Mms charges can be observed for both force fields it should be noted that they are heightened for ff99SB.