International Tables for Crystallography

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Ab initio phasing of low-resolution Fourier syntheses
V. Y. Lunin, A. G. Urzhumtsev and A. Podjarny. International Tables for Crystallography (2012). Vol. F, ch. 16.3, pp. 437-442  [ doi:10.1107/97809553602060000852 ]

Abstract

Low-resolution phasing addresses the cases where experimental X-ray diffraction intensities are only available to a low-resolution limit, or when the standard phasing methods to solve macromolecular structures fail. Ab initio phasing is based on general properties of macromolecular objects (connectivity, electron-density histograms, likelihood of molecular masks etc.) and does not require extra diffraction experiments. The Monte Carlo phasing procedure includes generation of a large `population' of trial solutions, enrichment of this population by filtering with selection criteria, clustering and averaging. The results of low-resolution phasing allow one to get information on the packing of particles in a crystal and on the shape (envelope) of the molecules, and to get an insight into the architecture of multidomain complexes.


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About International Tables for Crystallography

International Tables for Crystallography is the definitive resource and reference work for crystallography. The multi-volume series comprises articles and tables of data relevant to crystallographic research and to applications of crystallographic methods in all sciences concerned with the structure and properties of materials.