Intra-basepair Parameters Buckle(°) 14.99 Open angle(°) -11.74 Propeller (°) 16.07 Stagger (Å) 0.22 Shear (Å) -0.18 Stretch (Å) 2.89

Basepair Geometry C1'-C1' Distance(Å) 12.90 C6-C8 Distance (Å) 11.48 Opening (°) 171.35 Glycosidic angle- 1(°) 42.05 Glycosidic angle- 2(°) 33.3

Quantum Chemical interaction energy =-7.94 Kcal/mol

(Ref: Panigrahi et. al, Unpublished data )

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