Intra-basepair Parameters Buckle(°) -8.65 Open angle(°) -35.19 Propeller (°) 4.92 Stagger (Å) 0.22 Shear (Å) -0.49 Stretch (Å) 3.4

Basepair Geometry C1'-C1' Distance(Å) 9.74 C6-C8 Distance (Å) 4.96 Opening (°) 148.50 Glycosidic angle- 1 (°) 45.07 Glycosidic angle- 2 (°) 17.07

Quantum Chemical interaction energy = -3.94 Kcal/mol

(Ref: Panigrahi et.al ,Unpublished data)

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