Intra-basepair Parameters Buckle(°) -34.39 Open angle(°) -14.58 Propeller (°) 10.06 Stagger (Å) -0.04 Shear (Å) 0.13 Stretch (Å) 3.2

Basepair Geometry C1'-C1' Distance(Å) 8.94 C6-C8 Distance (Å) 10.5 Opening (°) 46.29 Glycosidic angle- 1(°) 112.15 Glycosidic angle- 2(°) 56.07

Quantum Chemical interaction energy = -9.26 Kcal/mol

(Ref: Panigrahi et. al, Unpublished data)

Intra-basepair parameters and basepair geometry are calculated by NUPARM.