Intra-basepair Parameters Buckle(°) 34.64 Open angle(°) -25.56 Propeller (°) -39.70 Stagger (Å) -0.45 Shear (Å) 2.40 Stretch (Å) 3.50

Basepair Geometry C1'-C1' Distance(Å) 7.84 C6-C8 Distance (Å) 8.98 Opening (°) 55.99 Glycosidic angle- 1 (°) 117.08 Glycosidic angle- 2 (°) 36.71

Quantum Chemical interaction energy = -16.11 Kcal/mol

(Ref: Unpublished data)

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