XmlmmCIF equivalent: diffrn_radiation Data items in the DIFFRN_RADIATION category describe the radiation used in measuring diffraction intensities, its collimation and monochromatisation before the sample. Post-sample treatment of the beam is described by data items in the DIFFRN_DETECTOR category. XmlmmCIF equivalent: diffrn_radiation/collimation The collimation or focusing applied to the radiation. XmlmmCIF equivalent: diffrn_radiation/filter_edge Absorption edge in angstroms of the radiation filter used. XmlmmCIF equivalent: diffrn_radiation/inhomogeneity Half-width in millimetres of the incident beam in the direction perpendicular to the diffraction plane. XmlmmCIF equivalent: diffrn_radiation/monochromator The method used to obtain monochromatic radiation. If a mono- chromator crystal is used the material and the indices of the Bragg reflection are specified. XmlmmCIF equivalent: diffrn_radiation/pdbx_diffrn_protocol SINGLE WAVELENGTH, LAUE, or MAD. XmlmmCIF equivalent: diffrn_radiation/pdbx_monochromatic_or_laue_m_l Monochromatic or Laue. XmlmmCIF equivalent: diffrn_radiation/pdbx_wavelength Wavelength of radiation. XmlmmCIF equivalent: diffrn_radiation/pdbx_wavelength_list Comma separated list of wavelengths or wavelength range. XmlmmCIF equivalent: diffrn_radiation/polarisn_norm The angle in degrees, as viewed from the specimen, between the perpendicular component of the polarisation and the diffraction plane. See _diffrn_radiation_polarisn_ratio. XmlmmCIF equivalent: diffrn_radiation/polarisn_ratio Polarisation ratio of the diffraction beam incident on the crystal. It is the ratio of the perpendicularly polarised to the parallel polarised component of the radiation. The perpendicular component forms an angle of _diffrn_radiation.polarisn_norm to the normal to the diffraction plane of the sample (i.e. the plane containing the incident and reflected beams). XmlmmCIF equivalent: diffrn_radiation/probe Name of the type of radiation used. It is strongly encouraged that this field be specified so that the probe radiation can be simply determined. XmlmmCIF equivalent: diffrn_radiation/type The nature of the radiation. This is typically a description of the X-ray wavelength in Siegbahn notation. XmlmmCIF equivalent: diffrn_radiation/wavelength_id This data item is a pointer to _diffrn_radiation_wavelength.id in the DIFFRN_RADIATION_WAVELENGTH category. XmlmmCIF equivalent: diffrn_radiation/xray_symbol The IUPAC symbol for the X-ray wavelength for probe radiation. XmlmmCIF equivalent: diffrn_radiation/diffrn_id This data item is a pointer to _diffrn.id in the DIFFRN category.