Describes CIF, the data exchange standard of crystallography. Provides: information for scientists who wish to record or use the results of a single-crystal or powder diffraction experiment; the data ontology necessary for designing interoperable computer applications; accompanying software including machine-readable CIF dictionaries, libraries and utility programs.
An essential guide and reference to CIF for programmers, data managers handling crystal-structure information and practising crystallographers.
The measure of absolute structure as defined by Rogers (1981). The value must lie in the 99.97% Gaussian confidence interval -1 -3u =< \h =< 1 + 3u and a standard uncertainty (e.s.d.) u must be supplied. The _enumeration_range of -1.0:1.0 is correctly interpreted as meaning (-1.0 - 3u) =< \h =< (1.0 + 3u). Ref: Rogers, D. (1981). Acta Cryst. A37, 734-741.