International
Tables for Crystallography Volume G Definition and exchange of crystallographic data Edited by S. R. Hall and B. McMahon © International Union of Crystallography 2006 |
International Tables for Crystallography (2006). Vol. G. ch. 2.5, p. 56
Section 2.5.5.4. Definition example 4: list data
a
School of Biomedical and Chemical Sciences, University of Western Australia, Crawley, Perth, WA 6009, Australia, and bBCI Ltd, 46 Uppergate Road, Stannington, Sheffield S6 6BX, England |
The definition of the number of hydrogen atoms attached to an atom site is shown in Fig. 2.5.5.4. The attributes _list and _list_reference signal whether the item is used in a list and what key item is in that list. As described in Chapters 2.1 and 2.2 , a CIF list is a two-dimensional table where data items are in the columns (headed by the data names) and the values are the rows. The attribute _list is yes if a data item may be used in a list. The attribute _list_reference specifies the key item as _atom_site_label. Each value of a key item must be unique so that the row of associated items can be accessed unambiguously. The attribute _enumeration_default specifies a default value for the defined item if it is absent from the data file.