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Improved R-factors for diffraction data analysis in macromolecular crystallography

Nature Structural Biology volume 4, pages 269–275 (1997)Cite this article

An Erratum to this article was published on 01 July 1997

Abstract

The quantity Rsym (also called Rmerge) is almost universally used for describing X-ray diffraction data quality. Here, we prove that Rsym is seriously flawed, because it has an implicit dependence on the redundancy of the data. A corrected R-factor, Rmeas, is introduced as the equivalent robust indicator of data consistency. In addition, we introduce Rmrgd, an R-factor that reflects the gain in accuracy upon averaging of equivalent reflections, as a useful indicator of the quality of reduced data. These new data quality indicators better reveal the benefits of highly redundant data and should stimulate improvements in data quality through increased merging of data from multiple crystals.

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Authors and Affiliations

  1. Universität Konstanz, Fakultät für Biologie, Postfach 5560 (M656), D-78434, Konstanz, Germany

    Kay Diederichs

  2. Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, NY, 14853, U.S.A.

    P. Andrew Karplus

Authors
  1. Kay Diederichs
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  2. P. Andrew Karplus
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Diederichs, K., Karplus, P. Improved R-factors for diffraction data analysis in macromolecular crystallography. Nat Struct Mol Biol 4, 269–275 (1997). https://doi.org/10.1038/nsb0497-269

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