Proton Reaction Path in Base Pairs of DNA Molecule According to the Complete Active Space Self-Consistent Field Method

The double proton transfer reaction paths in AT and CG base pairs of DNA molecule are calculated the Complete Active Space Self-Consistent Field method compared with same Density Functional Theory B3LYP approximation approach. We found that an essential increase activation energy, which significantly reduces probability spontaneous mutations via transfer. There exist two transition points on singlet potential energy surface divided by a flat region for GC pair. applicability various quantum-chemical methods description reactions was discussed.