DFT calculation of the binding between DNA base pairs and reaction substrates (AR, RZ, and RF). Optimized structure and IGMH (independent gradient model based on Hirshfeld partition) map (dginter = 0.05 a.u., isovalue = 0.004 a.u.) for AR-CG, AR-AT, RZ-CG, RZ-AT, RF-CG, and RF-AT. Values shown are binding energies in kcal/mol.