How parameters derived from the spot shape (such as mosaic block
               size and rotation, beam divergence, and crossfire) and their
	       errors were estimated. See the related items section.
	       This can be a written description or a citation to a specific
	       software package that determined these parameters.
	       Note, these parameters are considered derived terms from the
	       data, as opposed to measured terms from the instrument (such
	       as diffrn_radiation.div_x_source, a term similar to
	       pdbx_crystal_alignment.crossfire_x).