In the first two data points (at a strand separation of 0.0 Å and 0.22 Å), there is no stable energy minimum for the double proton transfer tautomeric form. Therefore, for the A*-T* configuration to be biologically relevant as a mutation mechanism, the DNA strands must first be separated by some distance as a criterion of spontaneous mutagenesis. Beyond this paradigm-shifting distance, the tautomeric configuration becomes more and more stable due to the potential energy surface having an increasing energy barrier. However, this energy barrier increase also requires greater energy to overcome. Therefore, we can conclude that the tautomeric form A*-T* becomes more stable under DNA separation but at the cost of the double proton transfer reaction becoming more unlikely.