Intra-basepair Parameters Buckle(°) 3.29 Open angle(°) -13.21 Propeller (°) -10.54 Stagger (Å) -0.08 Shear (Å) -0.4 Stretch (Å) 3.57

Basepair Geometry C1'-C1' Distance(Å) 10.00 C6-C8 Distance (Å) 5.24 Opening (°) 144.73 Glycosidic angle- 1 (°) 39.02 Glycosidic angle- 2 (°) 49.43

Quantum Chemical interaction energy = -8.17 Kcal/mol

(Ref: Panigrahi et al.,Unpublished data)

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