Intra-basepair Parameters Buckle(°) -67.45 Open angle(°) -44.44 Propeller (°) 33.28 Stagger (Å) -0.36 Shear (Å) 2.31 Stretch (Å) 4.00

Basepair Geometry C1'-C1' Distance(Å) 7.93 C6-C8 Distance (Å) 6.33 Opening (°) 94.82 Glycosidic angle- 1 (°) 35.34 Glycosidic angle- 2 (°) 70.03

Quantum Chemical interaction energy = -4.60 Kcal.mol

(Ref: Unpublished data)

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