Intra-basepair Parameters Buckle(°) -35.05 Open angle(°) 31.30 Propeller (°) -14.08 Stagger (Å) 0.87 Shear (Å) 3.57 Stretch (Å) 3.13

Basepair Geometry C1'-C1' Distance(Å) 8.50 C6-C8 Distance (Å) 8.72 Opening (°) 125.08 Glycosidic angle- 1 (°) 76.71 Glycosidic angle- 2 (°) 27.18

Quantum Chemical interaction energy = -8.62 Kcal/mol

(Ref: Panigrahi et al., Unpublished data)

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