Intra-basepair Parameters Buckle(°) 22.17 Open angle(°) -14.18 Propeller (°) -23.49 Stagger (Å) -1.88 Shear (Å) -0.97 Stretch (Å) 4.08

Basepair Geometry C1'-C1' Distance(Å) 5.55 C6-C8 Distance (Å) 9.58 Opening (°) 148.80 Glycosidic angle- 1 (°) 131.10 Glycosidic angle- 2 (°) 105.25

Quantum Chemical interaction energy = -6.66 Kcal/mol

(Ref: Unpublished data)

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