Table 4.
Charge transfer between bases (Δq in a.u.) and MEP values computed at 1.25 Å from hetero-atoms involved in Watson–Crick base pairs as hydrogen bond acceptors (a.u.)
| Stacked base | Stacking base | Optimized geometries | Experimental structures | ||||
|---|---|---|---|---|---|---|---|
| Δ(q) | MEP N1 | Δ(q) | MEP N1 | ||||
| A | A | −0.0062 | −0.0913 | 0.0086 | −0.0986 | ||
| A | C | 0.0096 | −0.0835 | 0.0099 | −0.0989 | ||
| A | G | 0.0053 | −0.0866 | 0.0056 | −0.1097 | ||
| A | U | 0.0205 | −0.0800 | 0.0151 | −0.0932 | ||
| Δ(q) | MEP N3 | MEP O2 | Δ(q) | MEP N3 | MEP O2 | ||
| C | A | −0.0096 | −0.0951 | −0.1075 | −0.0099 | −0.1079 | −0.1158 |
| C | C | 0.0000 | −0.0923 | −0.1064 | 0.0191 | −0.1009 | −0.1083 |
| C | G | −0.0021 | −0.0928 | −0.1051 | −0.0064 | −0.1067 | −0.1108 |
| C | U | 0.0118 | −0.0915 | −0.1017 | 0.0039 | −0.1037 | −0.1125 |
| Δ(q) | MEP O1 | Δ(q) | MEP O1 | ||||
| G | A | −0.0053 | −0.0698 | −0.0056 | −0.0780 | ||
| G | C | 0.0021 | −0.0689 | 0.0064 | −0.0751 | ||
| G | G | −0.0048 | −0.0754 | −0.0090 | −0.0774 | ||
| G | U | 0.0146 | −0.0665 | 0.0177 | −0.0701 | ||
| Δ(q) | MEP O1 | Δ(q) | MEP O1 | ||||
| U | A | −0.0205 | −0.0637 | −0.0151 | −0.0664 | ||
| U | C | −0.0118 | −0.0630 | −0.0039 | −0.0587 | ||
| U | G | −0.0146 | −0.0634 | −0.0177 | −0.0783 | ||
| U | U | 0.0000 | −0.0541 | 0.0008 | −0.0689 | ||