Intra-basepair Parameters Buckle(°) -7.53 Open angle(°) 0.85 Propeller (°) -2.29 Stagger (Å) -0.17 Shear (Å) 2.01 Stretch (Å) 2.99

Basepair Geometry C1'-C1' Distance(Å) 9.52 C6-C8 Distance (Å) 9.41 Opening (°) 104.89 Glycosidic angle- 1 (°) 87.79 Glycosidic angle- 2 (°) 10.64

Quantum Chemical interaction energy =- 4.88 Kcal/mol

(Ref: Panigrahi et. al, unpublished data)

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