CBF/imgCIF Extensions Dictionary

Draft version 1.5 for comment

[IUCr Home Page] [CIF Home Page] [CBF/imgCIF] [CBFlib]


Image dictionary (imgCIF) version 1.5.4




        The angle in degrees, as viewed from the specimen, between
               the normal to the polarization plane and the laboratory Y
               axis as defined in the AXIS category.

               Note that this is the angle of polarization of the source
               photons, either directly from a synchrotron beamline or
               from a monochromater.

               This differs from the value of
               in that _diffrn_radiation.polarisn_norm refers to
               polarization relative to the diffraction plane rather than
               to the laboratory axis system.

               In the case of an unpolarized beam, or a beam with true
               circular polarization, in which no single plane of
               polarization can be determined, the plane should be taken
               as the XZ plane and the angle as 0.

               See _diffrn_radiation.polarizn_source_ratio.

Type: float

Mandatory item: no

The permitted range is [-90.0, 90.0]

Enumeration default: 0.0

Category: diffrn_radiation

HTML version of draft dictionary created by modified version of makedicthtml by B. McMahon from modified version of imgCIF dcitionary 1.3.2 which is subject to the following copyright: