Intra-basepair Parameters Buckle(°) -5.18 Open angle(°) 19.4 Propeller (°) -2.59 Stagger(Å) 0.00 Shear(Å) 2.6 Stretch(Å) 2.62

Basepair Geometry C1'-C1' Distance (Å) 10.08 C6-C8 Distance(Å) 7.39 Opening (°) 66.88 Glycosidic angle- 1(°) 68.71 Glycosidic angle- 2(°) 44.6

Quantum Chemical interaction energy = -6.22 Kcal/mol

(Ref: Panigrahi et. al, unpublished data)

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