Table 1.
X-ray data collection and refinement statistics
| Cd2+-DQAQB state (dark) | Cd2+-D+QAQB− state (light) | Zn2+-DQAQB state (dark) | |
|---|---|---|---|
| Data collection | |||
| Maximum resolution, Å | 2.49 | 2.49 | 2.49 |
| Total observations (unique) | 94,449 (13,013) | 92,263 (12,363) | 94,967 (12,576) |
| Redundancy* | 3.9 | 3.9 | 3.9 |
| Mean I/σ(I)† (highest resolution shell) | 8.8 (3.6) | 7.0 (2.3) | 7.0 (2.3) |
| Rsym‡ (highest resolution shell), % | 6.5 (21.0) | 8.9 (33.4) | 8.1 (32.8) |
| Completeness§ (last shell), % | 99.1 (94.9) | 95.5 (88.4) | 96.7 (89.0) |
| Refinement | |||
| Resolution range, Å | 50–2.50 | 50–2.50 | 50–2.50 |
| Reflections | 93,504 | 92,156 | 94,672 |
| R factor,¶ % | 22.7 | 22.6 | 23.8 |
| Rfree,∥ % | 25.7 | 25.2 | 26.5 |
| Deviation from ideal bond lengths, Å | 0.012 | 0.013 | 0.014 |
| Deviation from ideal bond angles, ° | 1.7 | 1.6 | 1.7 |
*Ratio of the total number of reflections measured to the total number of unique reflections.
†I/σ(I) is the ratio of the average of the diffraction intensities to the average background intensity.
‡ Rsym = Σhkl Σj|Ihkl − 〈Ihkl〉|/ΣhklΣj|Ihkl|, where 〈Ihkl〉 is the average intensity for a set of j symmetry-related reflections and Ihkl is the value of the intensity for a single reflection within a set of symmetry-related reflections.
§ Completeness is the ratio of the number of reflections measured to the total number of possible reflections.
¶ R factor = (Σhkl|Fo| − |Fc|)/Σhkl|Fo| where |Fo| is the observed structure factor amplitude and |Fc| is the calculated structure factor amplitude.
∥Rfree = (Σhkl,T|Fo| − |Fc|)/Σhkl,T|Fo|, where a test set, T (5% of the data), is omitted from the refinement.