Table 2. Refined parameters of the two Br atoms in crystals of d(CGCG[BrU]G).
Refinement was carried out in SHARP against unmerged data from all three crystal orientations. Crystal orientation data were used to compute the p and p′ vectors for each reflection record. The AAS properties of the Br atoms were modelled by second-rank symmetric f′′ tensors with refineable elements.
| Parameters | Br 1 | Br 2 |
|---|---|---|
| x | 0.0512 (2) | 0.6016 (2) |
| y | 0.3094 (1) | 0.7257 (1) |
| z | 0.7750 (1) | 0.4925 (1) |
| B (Å2) | 13.1 (2) | 12.7 (2) |
| Baniso (Å2) |  |
 |
| Occupancy | 1 (not refined) | 1 (not refined) |
| f′ | −9.5 (not refined) | −9.5 (not refined) |
| f′′ tensor |  |
 |
| Eigenvalues of f′′ | 1.28, 1.55, 9.23 | 1.32, 1.40, 10.52 |
| Eigenvector corresponding to the largest eigenvalue |  |
 |
| Direction of C—Br bond |  |
 |