TABLE 6.
Enthalpy (top) and Free Energy (bottom) of tautomerization for DNA and RNA basepairs in the gas phase. All quantities are in kcal/mol.
| CBS | G3B3 | G3MP2 | PBE0 | B1B95 | B3LYP | QCRNA | |
|---|---|---|---|---|---|---|---|
| Enthalpy | |||||||
| Adenine | 12.5 | 11.7 | 11.4 | 12.3 | 12.2 | 11.9 | 11.9 |
| Cytosine | 1.2 | 1.0 | 0.8 | 2.4 | 2.4 | 2.1 | 2.1 |
| Guanine | −0.4 | −0.2 | −0.3 | 0.7 | 0.5 | 1.1 | 1.1 |
| Thymine | 12.0 | 11.8 | 11.6 | 12.3 | 11.9 | 12.5 | 12.5 |
| Uracil | 11.1 | 10.9 | 10.7 | 11.3 | 10.9 | 11.6 | 11.5 |
| Free Energy | |||||||
| Adenine | 12.3 | 12.0 | 11.7 | 13.6 | 13.4 | 13.0 | 12.8 |
| Cytosine | 1.5 | 1.2 | 1.0 | 3.4 | 3.8 | 3.0 | 3.4 |
| Guanine | −0.3 | 0.0 | −0.1 | 0.8 | 0.6 | 1.2 | 1.2 |
| Thymine | 12.2 | 12.0 | 11.8 | 12.5 | 12.0 | 12.7 | 12.6 |
| Uracil | 11.2 | 11.1 | 10.8 | 11.4 | 11.1 | 11.7 | 11.6 |