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Calibration of rotation axes for multi‐axis goniometers in macromolecular crystallography
Author(s) -
White K. Ian,
Bugris Valeria,
McCarthy Andrew A.,
Ravelli Raimond B. G.,
Csankó Krisztián,
Cassetta Alberto,
Brockhauser Sandor
Publication year - 2018
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s1600576718010956
Subject(s) - goniometer , calibration , rotation (mathematics) , sample (material) , optics , rotation around a fixed axis , accuracy and precision , physics , symmetry (geometry) , diffraction , computer science , computer vision , mathematics , geometry , classical mechanics , quantum mechanics , thermodynamics
The installation of multi‐axis goniometers such as the ESRF/EMBL miniKappa goniometer system has allowed the increased use of sample reorientation in macromolecular crystallography. Old and newly appearing data collection methods require precision and accuracy in crystal reorientation. The proper use of such multi‐axis systems has necessitated the development of rapid and easy to perform methods for establishing and evaluating device calibration. A new diffraction‐based method meeting these criteria has been developed for the calibration of the motors responsible for rotational motion. This method takes advantage of crystal symmetry by comparing the orientations of a sample rotated about a given axis and checking that the magnitude of the real rotation fits the calculated angle between these two orientations. Hence, the accuracy and precision of rotational motion can be assessed. This rotation calibration procedure has been performed on several beamlines at the ESRF and other synchrotrons. Some resulting data are presented here for reference.