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 labels of the three atom sites which define the angle given by _geom_angle. These must match labels specified as _atom_site_label in the atom list. Label 2 identifies the site at the apex of the angle.
Appears in list as essential element of loop structure
Must match data name_atom_site_label