Orientation Reflection#
An orientation reflection is a peak intensity (typically an
observation) due to diffraction from a specific orientation of a crystalline
sample with respect to the incident radiation. The reflection occurs for a
precise alignment of the sample’s crystalline planes and diffractometer axes
with the incoming radiation. Information for each reflection is stored in
an instance of hklpy2.blocks.reflection.Reflection().
The coordinates of two (or more) reflections are used to compute a sample’s \(UB\) orientation matrix. \(UB\) transforms between the sample’s crystallographic axes (reciprocal-space) and the diffractometer’s physical axes (real-space).
Each reflection is defined by:
full set of diffractometer angles - real axes
reciprocal-space coordinates - pseudo axes
wavelength of the incident radiation
Note that the engineering units for the pseudo axes are the reciprocal of the units of the wavelength (where angstroms is typical). The angles are reported in degrees.
Reflections are stored as part of the sample.
Examples
Many of the Examples (such as E4CH, E4CV, and K4CV) show how to create or add a reflection.
See also