 Atom-site symmetry and disorder in the IUCr core CIF dictionary

Primary coreCIF2.4.5 definition: number of distinct sites generated by space-group symmetry, equal to general-position multiplicity divided by site-symmetry order. Companion disorder-group definition www.iucr.org/__data/iucr/cifdic_html/1/cif_core.dic/Iatom_site_disorder_group.html distinguishes jointly occupied sites within one group from alternative groups.