Intra-basepair Parameters Buckle(°) -14.76 Open angle(°) 19.56 Propeller (°) -26.22 Stagger (Å) -0.85 Shear (Å) -3.78 Stretch (Å) 4.86

Basepair Geometry C1'-C1' Distance(Å) 5.54 C6-C8 Distance (Å) 9.57 Opening (°) 145.97 Glycosidic angle- 1 (°) 105.23 Glycosidic angle- 2 (°) 131.89

Quantum Chemical interaction energy = -8.58 Kcal/mol

(Ref: Panigrahi et. al., Unpublished data)

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