Intra-basepair Parameters Buckle(°) 18.94 Open angle(°) -21.03 Propeller (°) -70.75 Stagger (Å) -1.23 Shear (Å) 1.31 Stretch (Å) 3.37

Basepair Geometry C1'-C1' Distance(Å) 10.31 C6-C8 Distance (Å) 7.41 Opening (°) 92.96 Glycosidic angle- 1 (°) 48.59 Glycosidic angle- 2 (°) 31.84

Quantum Chemical interaction energy = -8.95 Kcal/mol

(Ref: Panigrahi et al., Unpublished data)

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