Intra-basepair Parameters Buckle(°) 10.93 Open angle(°) -6.36 Propeller (°) -14.61 Stagger (Å) -0.10 Shear (Å) 2.65 Stretch (Å) 3.21

Basepair Geometry C1'-C1' Distance(Å) 11.43 C6-C8 Distance (Å) 6.70 Opening (°) 178.71 Glycosidic angle- 1 (°) 15.21 Glycosidic angle- 2 (°) 17.07

Quantum Chemical interaction energy = -8.22 Kcal/mol

(Ref: Unpublished data)

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