Studies of Hydrogen‐Bonded Systems. IV. Radiation‐Induced Tunneling and Tautomeric Equilibria in the Guanine—Cytosine Base Pair

Electronic energies are calculated for the ground states of the cation and anion of the guanine—cytosine base pair, using an approximate self‐consistent‐field method described earlier by the authors. The calculations are made for a series of positions of the hydrogen‐bonded protons, all three of which are explicitly included in the formulation. The results are used to discuss equilibria and proton tunneling between tautomeric forms, and an indication is given of the possible connection between these phenomena and radiation‐induced mutation.