International Tables for Crystallography

Locating heavy-atom sites
M. T. Stubbs and R. Huber. International Tables for Crystallography (2012). Vol. F, ch. 12.2, pp. 327-332  [ doi:10.1107/97809553602060000838 ]


In order to obtain phase information from isomorphous replacement (or from anomalous dispersion), it is necessary to locate the atomic positions of the heavy-atom (or anomalous) scatterers. The topics covered in this chapter include: the origin of the phase problem; the Patterson function; difference Fourier maps; treatment of errors; automated search procedures; and special complications such as lack of isomorphism, space-group problems and high levels of substitution.

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About International Tables for Crystallography

International Tables for Crystallography is the definitive resource and reference work for crystallography. The series consists of eight volumes and 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.