Intra-basepair Parameters Buckle(°) -1.93 Open angle(°) -16.43 Propeller (°) 36.52 Stagger (Å) 0.81 Shear (Å) 0.07 Stretch (Å) 3.52

Basepair Geometry C1'-C1' Distance(Å) 10.13 C6-C8 Distance (Å) 7.35 Opening (°) 97.85 Glycosidic angle- 1 (°) 48.39 Glycosidic angle- 2 (°) 21.65

Quantum Chemical interaction energy = -9.01 Kcal/mol

(Ref: Panigrahi et al., Unpublished data)

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