International Tables for Crystallography (2012). Vol. F, ch. 13.4, pp. 352-363   | 1 | 2 |
doi: 10.1107/97809553602060000842

Chapter 13.4. Noncrystallographic symmetry averaging of electron density for molecular-replacement phase refinement and extension

Contents

  • 13.4. Noncrystallographic symmetry averaging of electron density for molecular-replacement phase refinement and extension  (pp. 352-363) | html | pdf | chapter contents |
    • 13.4.1. Introduction  (p. 352) | html | pdf |
    • 13.4.2. Noncrystallographic symmetry (NCS)  (pp. 352-354) | html | pdf |
    • 13.4.3. Phase determination using NCS  (p. 354) | html | pdf |
    • 13.4.4. The p - and h -cells  (pp. 354-355) | html | pdf |
    • 13.4.5. Combining crystallographic and noncrystallographic symmetry  (pp. 355-356) | html | pdf |
      • 13.4.5.1. General considerations  (p. 355) | html | pdf |
      • 13.4.5.2. Averaging with the p -cell  (pp. 355-356) | html | pdf |
      • 13.4.5.3. Averaging the p -cell and placing the results into the h -cell  (p. 356) | html | pdf |
    • 13.4.6. Determining the molecular envelope  (pp. 356-357) | html | pdf |
    • 13.4.7. Finding the averaged density  (pp. 357-358) | html | pdf |
    • 13.4.8. Interpolation  (p. 358) | html | pdf |
    • 13.4.9. Combining different crystal forms  (p. 358) | html | pdf |
    • 13.4.10. Phase extension and refinement of the NCS parameters  (p. 359) | html | pdf |
    • 13.4.11. Convergence  (pp. 359-360) | html | pdf |
    • 13.4.12. Ab initio phasing starts  (p. 360) | html | pdf |
    • 13.4.13. Recent salient examples in low-symmetry cases: multidomain averaging and systematic applications of multiple-crystal-form averaging  (pp. 360-361) | html | pdf |
    • 13.4.14. Programs  (p. 361) | html | pdf |
    • References | html | pdf |
    • Figures
      • Fig. 13.4.2.1. The two-dimensional periodic design shows crystallographic twofold axes perpendicular to the page and local noncrystallographic rotation axes in the plane of the paper (design by Audrey Rossmann)  (p. 352) | html | pdf |
      • Fig. 13.4.2.2. ( a ) NCS in a triclinic cell  (p. 353) | html | pdf |
      • Fig. 13.4.2.3. The position of the twofold rotation axis which relates the two piglets is completely arbitrary  (p. 353) | html | pdf |
      • Fig. 13.4.4.1. Stereographic projections showing alternative definitions of the `standard orientation' of an icosahedron in the h -cell  (p. 355) | html | pdf |
      • Fig. 13.4.6.1. The volume of the molecular mask expressed as a percentage of the volume of the p -cell asymmetric unit, as determined by the density cutoff in the h -cell  (p. 357) | html | pdf |
      • Fig. 13.4.8.1. Interpolation box for finding the approximate electron density at G x , Δ y , Δ z ), given the eight densities at the corners of the box  (p. 358) | html | pdf |
      • Fig. 13.4.11.1. Plot of a correlation coefficient as the phases were extended from 8 to 3 Å resolution in the structure determination of Mengo virus  (p. 359) | html | pdf |
      • Fig. 13.4.12.1. Structure amplitudes of the type II crystals of southern bean mosaic virus, averaged within shells of reciprocal space, shown in relation to the Fourier transform of a 284 Å diameter sphere  (p. 360) | html | pdf |
    • Tables
      • Table 13.4.7.1. Mean root-mean-square scatter between noncrystallographically related points  (p. 357) | html | pdf |