Intra-basepair Parameters Buckle(°) 2.48 Open angle(°) 12.74 Propeller (°) -0.28 Stagger (Å) -0.01 Shear (Å) -2.65 Stretch (Å) 2.74

Basepair Geometry C1'-C1' Distance(Å) 8.39 C6-C8 Distance (Å) 11.2 Opening (°) 70.11 Glycosidic angle-1(°) 118.31 Glycosidic angle-2(°) 81.27

Quantum Chemical interaction energy = -4.38 Kcal/mol

(Ref: Panigrahi et. al, Unpublished data)

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