Core dictionary (coreCIF) version 2.4.5
Data items in the DIFFRN_RADIATION_WAVELENGTH category describe the wavelength of the radiation used in measuring the diffraction intensities. Items may be looped to identify and assign weights to distinct wavelength components from a polychromatic beam.Example:
Example 1 - based on data set TOZ of Willis, Beckwith & Tozer
[Acta Cryst. (1991), C47, 2276-2277].