International Tables for Crystallography (2012). Vol. F, ch. 9.1, pp. 211-230   | 1 | 2 |
doi: 10.1107/97809553602060000824

Chapter 9.1. Principles of monochromatic data collection

Contents

  • 9.1. Principles of monochromatic data collection  (pp. 211-230) | html | pdf | chapter contents |
    • 9.1.1. Introduction  (p. 211) | html | pdf |
    • 9.1.2. The components of a monochromatic X-ray experiment  (p. 211) | html | pdf |
    • 9.1.3. Data completeness  (p. 211) | html | pdf |
    • 9.1.4. X-ray sources  (pp. 211-212) | html | pdf |
      • 9.1.4.1. Conventional sources  (pp. 211-212) | html | pdf |
      • 9.1.4.2. Synchrotron storage rings  (p. 212) | html | pdf |
    • 9.1.5. Goniostat geometry  (pp. 212-213) | html | pdf |
      • 9.1.5.1. Overview  (p. 212) | html | pdf |
      • 9.1.5.2. The screenless rotation method and 2D detectors  (pp. 212-213) | html | pdf |
    • 9.1.6. Basis of the rotation method  (pp. 213-217) | html | pdf |
      • 9.1.6.1. Rotation geometry  (p. 213) | html | pdf |
      • 9.1.6.2. Diffraction pattern at a single orientation: the `still' image  (pp. 213-214) | html | pdf |
      • 9.1.6.3. Rocking curve: crystal mosaicity and beam divergence  (p. 214) | html | pdf |
      • 9.1.6.4. Rotation images and lunes  (p. 214) | html | pdf |
      • 9.1.6.5. Partially and fully recorded reflections  (pp. 214-215) | html | pdf |
      • 9.1.6.6. The width of the rotation range per image: fine ϕ slicing  (p. 215) | html | pdf |
      • 9.1.6.7. Wide slicing  (pp. 215-217) | html | pdf |
    • 9.1.7. Rotation method: geometrical completeness  (pp. 217-221) | html | pdf |
      • 9.1.7.1. Total rotation range for non-anomalous data  (pp. 217-219) | html | pdf |
      • 9.1.7.2. Total rotation range for anomalous-dispersion data  (pp. 219-220) | html | pdf |
      • 9.1.7.3. Blind region  (pp. 220-221) | html | pdf |
      • 9.1.7.4. Alternative indexing  (p. 221) | html | pdf |
    • 9.1.8. Crystal-to-detector distance  (pp. 221-222) | html | pdf |
    • 9.1.9. Wavelength  (p. 222) | html | pdf |
    • 9.1.10. Lysozyme as an example  (pp. 222-223) | html | pdf |
    • 9.1.11. Rotation method: qualitative factors  (pp. 223-225) | html | pdf |
      • 9.1.11.1. Inspection of reflection profiles  (pp. 223-224) | html | pdf |
      • 9.1.11.2. Exposure time  (p. 224) | html | pdf |
      • 9.1.11.3. Overloads  (p. 224) | html | pdf |
      • 9.1.11.4. R factor, I /σ( I ) ratio and estimated uncertainties  (pp. 224-225) | html | pdf |
    • 9.1.12. Radiation damage  (pp. 225-226) | html | pdf |
      • 9.1.12.1. Historical perspective  (p. 225) | html | pdf |
      • 9.1.12.2. Cryogenic vitrification  (pp. 225-226) | html | pdf |
      • 9.1.12.3. High-intensity third-generation SR sources  (p. 226) | html | pdf |
      • 9.1.12.4. Correcting data for the effects of radiation damage  (p. 226) | html | pdf |
    • 9.1.13. Relating data collection to the problem in hand  (pp. 226-228) | html | pdf |
      • 9.1.13.1. Isomorphous-anomalous derivatives  (pp. 226-227) | html | pdf |
      • 9.1.13.2. Anomalous scattering, MAD and SAD  (p. 227) | html | pdf |
      • 9.1.13.3. Molecular replacement  (p. 227) | html | pdf |
      • 9.1.13.4. Definitive data for refinement of protein models  (pp. 227-228) | html | pdf |
      • 9.1.13.5. A series of mutant or complex structures  (p. 228) | html | pdf |
      • 9.1.13.6. Atomic resolution applications  (p. 228) | html | pdf |
    • 9.1.14. The importance of low-resolution data  (p. 228) | html | pdf |
    • 9.1.15. Data quality over the whole resolution range  (pp. 228-229) | html | pdf |
    • 9.1.16. Strategies for automated data acquisition  (p. 229) | html | pdf |
    • 9.1.17. Final remarks  (p. 229) | html | pdf |
    • References | html | pdf |
    • Figures
      • Fig. 9.1.6.1. The Ewald-sphere construction  (p. 213) | html | pdf |
      • Fig. 9.1.6.2. The plane of reflections in the reciprocal sphere that is approximately perpendicular to the X-ray beam gives rise to an ellipse of reflections on the detector  (p. 213) | html | pdf |
      • Fig. 9.1.6.3. Schematic representation of beam divergence (δ) and crystal mosaicity (η)  (p. 214) | html | pdf |
      • Fig. 9.1.6.4. A single lune on two consecutive exposures  (p. 215) | html | pdf |
      • Fig. 9.1.6.5. Appearance of a lune for (left) a crystal of low mosaicity and (right) a highly mosaic crystal  (p. 215) | html | pdf |
      • Fig. 9.1.6.6. The width of the lunes is proportional to the rotation range per image, Δϕ, which increases from ( a ) to ( c )  (p. 216) | html | pdf |
      • Fig. 9.1.6.7. The largest allowed rotation range per exposure depends on the dimension of the primitive unit cell oriented along the X-ray beam; this is diminished by high mosaicity  (p. 216) | html | pdf |
      • Fig. 9.1.6.8. If the crystal lattice is centred or if its orientation is non-axial, the reflections do not overlap in spite of overlapping lunes, as illustrated on the right with consecutive layers of reflections viewed from the side  (p. 216) | html | pdf |
      • Fig. 9.1.7.1. Rotation of a triclinic crystal by 180° in the X-ray beam, represented as rotating the Ewald sphere with a stationary crystal, projected along the rotation axis  (p. 218) | html | pdf |
      • Fig. 9.1.7.2. Rotation of a triclinic crystal by 135° is not sufficient to obtain totally complete data  (p. 218) | html | pdf |
      • Fig. 9.1.7.3. After a 90° rotation out of a required 180°, the overall completeness is higher than 50%  (p. 218) | html | pdf |
      • Fig. 9.1.7.4. For an orthorhombic crystal, a 90° rotation is sufficient provided the starting or final orientation is along the major axis  (p. 219) | html | pdf |
      • Fig. 9.1.7.5. Rotation of an orthorhombic crystal by 90° between two diagonal orientations leaves a part of the reciprocal space unmeasured  (p. 219) | html | pdf |
      • Fig. 9.1.7.6. For data containing an anomalous signal, when both Bijvoet mates have to be measured, 180° rotation of a triclinic crystal is not sufficient and at least an additional [2\theta_{\max}] is required  (p. 220) | html | pdf |
      • Fig. 9.1.7.7. Rotation by 360° leaves the part of the reciprocal space in the blind region unmeasured, since the reflections near the rotation axis do not cross the surface of the Ewald sphere  (p. 220) | html | pdf |
      • Fig. 9.1.7.8. Dependence of the total fraction of reflections in the blind region on the resolution for three different wavelengths: 1.54, 1 and 0.71 Å  (p. 220) | html | pdf |
      • Fig. 9.1.7.9. For shorter wavelengths the blind region is narrower, since the Ewald sphere is flatter  (p. 220) | html | pdf |
      • Fig. 9.1.7.10. If the crystal has a symmetry axis, it should be skewed from the rotation axis by at least [\theta_{\max}] to be able to collect the reflections equivalent to those in the blind region  (p. 221) | html | pdf |
      • Fig. 9.1.10.1. Images recorded from a crystal of lysozyme  (p. 223) | html | pdf |
    • Tables
      • Table 9.1.1.1. Size of the unit cell and number of reflections  (p. 211) | html | pdf |
      • Table 9.1.7.1. Standard choice of asymmetric unit in reciprocal space for different point groups from the CCP4 program suite  (p. 217) | html | pdf |
      • Table 9.1.7.2. Rotation range (°) required in different crystal classes  (p. 219) | html | pdf |
      • Table 9.1.7.3. Space groups with alternative, non-equivalent indexing schemes  (p. 221) | html | pdf |