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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. 25.1, p. 688
Section 25.1.3.5. SCALA
a
Biomolecular Crystallography Laboratory, CABM & Rutgers University, 679 Hoes Lane, Piscataway, NJ 08854-5638, USA, and Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Yue-Yang Road, Shanghai 200 031, People's Republic of China, and bBiomolecular Crystallography Laboratory, CABM & Rutgers University, 679 Hoes Lane, Piscataway, NJ 08854-5638, USA |
The SCALA program (P. R. Evans, 1993![[link]](/graphics/greenarr.gif)
, 1997) scales together multiple observations of reflections, and (optionally) merges multiple observations into an averaged intensity. Various scaling models are implemented. The scale factor is a function of the primary beam direction, either as a smooth function of φ (the rotation angle), or expressed as batch (image) number. In addition, the scale may be a function of the secondary beam direction derived from the spatial coordinates of the measured spot on the detector. In this case, the scaling is an interpolated three-dimensional function similar to that described by Kabsch (1988). The merging algorithm analyses the data for outliers and gives detailed analyses. It generates weighted means of the observations of the same reflection, after rejecting the outliers.
Location: SCALA is part of the CCP4 suite (Section 25.1.2.4). Operating systems: UNIX and VAX/VMS. Type: source code and binary. Distribution: free academic.
References
Evans, P. R. (1993). Data reduction. In Proceedings of the CCP4 study weekend. Data collection and processing, edited by L. Sawyer, N. W. Isaacs & S. Bailey, pp. 114–122. Warrington: Daresbury Laboratory.Google Scholar
Evans, P. R. (1997). Scaling of MAD data. In Proceedings of the CCP4 study weekend. Recent advances in phasing, edited by M. Winn, Vol. 33, pp. 22–24.Google Scholar
Kabsch, W. (1988). Evaluation of single-crystal X-ray diffraction data from a position-sensitive detector. J. Appl. Cryst. 21, 916–924.Google Scholar
