International
Tables for Crystallography Volume F Crystallography of biological macromolecules Edited by M. G. Rossmann and E. Arnold © International Union of Crystallography 2006 |
International Tables for Crystallography (2006). Vol. F. ch. 11.5, p. 240
Section 11.5.7.3. Statistics for rejecting reflections and data quality as a function of frame number
a
Department of Biological Sciences, Purdue University, West Lafayette, IN 47907-1392, USA |
The behaviour of the R factor versus frame number (Fig. 11.5.7.5) is more monotonic when method 1 is used compared to method 2. In method 1, the data-quality estimates for neighbouring frames are strongly correlated because the full reflections used in the statistics are obtained by summing partials from consecutive frames. By contrast, in method 2 every frame produces estimates of full reflection intensities independently of the neighbouring frames. Therefore, the R factors per frame calculated after scaling with method 2 truly represent the data quality for individual frames.