Intra-basepair Parameters Buckle(°) -61.73 Open angle(°) -27.18 Propeller (°) -27.85 Stagger (Å) -1.42 Shear (Å) 0.52 Stretch (Å) 4.19

Basepair Geometry C1'-C1' Distance(Å) 7.88 C6-C8 Distance (Å) 7.02 Opening (°) 13.80 Glycosidic angle- 1 (°) 26.68 Glycosidic angle- 2 (°) 107.0

Quantum Chemical interaction energy = -12.96 Kcal/mol

(Ref: Panigrahi et.al ,Unpublished data)

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