Intra-basepair Parameters Buckle(°) -50.71 Open angle(°) -105.44 Propeller (°) -89.95 Stagger (Å) 3.34 Shear (Å) 0.16 Stretch (Å) -0.99

Basepair Geometry C1'-C1' Distance(Å) 7.56 C6-C8 Distance (Å) 8.07 Opening (°) 16.51 Glycosidic angle- 1 (°) 37.55 Glycosidic angle- 2 (°) 99.05

Quantum Chemical interaction energy = -10.51 Kcal/mol

(Ref: Panigrahi et.al , Unpublished data)

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