Intra-basepair Parameters Buckle(°) 17.50 Open angle(°) -13.43 Propeller (°) 18.22 Stagger (Å) -1.13 Shear (Å) -2.63 Stretch (Å) 3.01

Basepair Geometry C1'-C1' Distance(Å) 6.59 C6-C8 Distance (Å) 6.67 Opening (°) 3.78 Glycosidic angle- 1 (°) 32.68 Glycosidic angle- 2 (°) 144.26

Quantum Chemical interaction energy = -10.17 Kcal/mol

(Ref: Unpublished data)

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