Intra-basepair Parameters Buckle(°) -13.41 Open angle(°) -9.57 Propeller (°) 4.63 Stagger (Å) 0.2 Shear (Å) 2.2 Stretch (Å) 3.06

Basepair Geometry C1'-C1' Distance(Å) 12.37 C6-C8 Distance (Å) 8.53 Opening (°) 124.09 Glycosidic angle- 1 (°) 26.44 Glycosidic angle- 2 (°) 24.95

Quantum Chemical interaction energy = -11.48 Kcal/mol

(Ref: Panigrahi et.al ,Unpublished data)

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