Statistics of diffraction data collection
The data shown in green need only be specified for datasets where the anomalous differences are used (e.g., for phasing derivatives). To get these statistics the option "Separate anomalous pairs for merging statistics" needs to be activated in AIMLESS.
Example for a refinement statistics table
| found in | ||
|---|---|---|
| X-ray source | BESSY BL14.3 | experimental notes |
| Wavelength (Å) | 0.9537 | experimental notes |
| Data-collection temperature (K) | 100 | experimental notes |
| Space group | P21 | |
| Resolution limits (Å) * | 45 - 1.9 (2.2 - 1.9) | AIMLESS log file summary |
| Unit cell parameters (Å, °) | a=98.9, b=113.4, c=91.3, β=110.3 | AIMLESS log file summary |
| Unique reflections | 129,723 | AIMLESS log file summary |
| Multiplicity | 5.2 (5.1) | AIMLESS log file summary |
| Anomalous multiplicity | 2.6 (2.5) | AIMLESS log file summary |
| Completeness (%) * | 94.5 (95.3) | AIMLESS log file summary |
| Anomalous completeness (%) * | 86.5 (87.0) | AIMLESS log file summary |
| mean(I/sigma(I)) * | 48.1 (5.6) | AIMLESS log file summary |
| Rmerge * (=Rsym) | 5.0 (48.5) | AIMLESS log file summary (use all I+ & I-) |
| Rpim * | 2.1 (17.5) | AIMLESS log file summary (use all I+ & I-) |
| CC(1/2)* | 0.999 (0.365) | AIMLESS log file summary |
| DelAnom CC(1/2) * | 0.876 (0.302) | AIMLESS log file summary |
| Mosaicity (°) | 0.56 | AIMLESS log file summary |
| Wilson B factor (Å2) | 20.3 | AIMLESS log file summary or graph of Wilson plot |
| Number of molecules per a.u. | 2 | after structure determination |
| Solvent content (%) | 56 | after structure determination in the "Density Improvement" or "Cell Content Analysis" step |
| * Values in parentheses refer to the highest resolution shell | ||
| parameter | short explanation |
|---|---|
| Unique reflections | the number of symmetry related reflections for which intensities have been measured |
| Multiplicity | the average number of measurements of the unique reflections (# of measured reflections / # of unique reflections). |
| Anomalous multiplicity | the average number of measurements of each reflections if the Bijvoet pairs are not merged (considered equivalent) |
| Completeness (%) | number of measured unique reflections / number of all possible unique reflections to this resolution |
| Anomalous completeness (%) | dito for the anomalous data (Friedel pairs not merged) |
| mean(I/sigma(I)) | mean average intensity / average intensity error |
| Rsym | Rfactor for merging the symmetry related reflections. See lecture script. |
| Rpim | Precision indicating merging Rfactor. |
| CC(1/2) | Correlation of the intensities of two randomly chosen half-datasets. |
| DelAnom CC(1/2) | Correlation of the intensities of two randomly chosen half-datasets between the Friedel mates. |
| Mosaicity (°) | see lecture script |
| Wilson B factor (Å2) | The Wilson B factor is obtained from an analysis of a plot of the average reflection intensity vs. sin2(theta)/lamda2 (the Wilson plot). The Wilson B factor indicates the degree of order in the crystal. It is an approximation of the average atomic B factors which may be later obtained in refinement. If the B factor is high (> 50 Å2), there is significant disorder in the crystal and it may be difficult to determine all parts of the protein structure even if the resolution is sufficient. |