As described in the Introduction, the electrostatic potential is a property that can be derived from the electron density and has been used to explain the site-specific binding of proteins and counterions. To assess the accuracy of model-calculated DNA electrostatic potentials, single base pair structures of both the A/T and G/C base pairs were investigated, as the electrostatic potentials for these base pairs are well-studied. The major and minor grooves carry electronic signatures that distinguish the base pairs and make them uniquely recognizable to interacting molecules. On the major groove side, the G/C pair shows a strong polarity across the hydrogen bond (Fig. ) whereas the A/T base pair has a positive amine group in its center, resulting in an overall neutral to weakly negative potential (Fig. ). On the minor groove side, while both base pairs have negative potentials, the A/T base pair is more strongly negative since it lacks the positive amine group.