Events in the third (first) quadrant of the FES correspond to the L (R) tautomer where both the protons are covalently bonded to the donor (acceptor) oxygen atoms. Therefore, in these two quadrants, the DPT junction is neutral as the participating carboxylate groups have one hydrogen atom each. On the other hand, events in the second and fourth quadrants correspond to the state of charged DPT junction where both the hydrogen atoms are near to one of the carboxylate groups. At 70 K, for the classical nuclei, since there are no proton transfer events, we observe a single local minima in the third quadrant (Figure . This implies that the proton is significantly more delocalized along the hydrogen bonds, fully consistent with previous studies reporting this effect in numerous other organic molecular systems. Furthermore, the free energy profile extends to the second and fourth quadrant forming an elbow suggesting presence of charged DPT junctions where both the transferring protons are close to the same molecule.