Table 2. Geometry and binding energies of stacked CG base pairs from B97-D/def2-TZVP (Å, ° and kcal/mol).

	Cent… Cent a	Dihedral a	Binding Energy
C	3.381	9.0	-16.07
5-mC	3.310	12.5	-17.52
5-hC	3.361	9.4	-22.12
5-fC	3.451	2.9	-14.65
5-caC	3.823	32.6	-15.56

^a Cent…Cent refers to the distance between centroids of 6-membered rings; Dihedral refers to the angle between mean planes of rings.