International Tables for Crystallography (2026). Vol. G. Early view chapter
https://doi.org/10.1107/97809553602060000994

Chapter 2.4. Data definition languages for CIF dictionaries

Contents

  • Data definition languages for CIF dictionaries | html | pdf | chapter contents |
    James R. Hester and Nick Spadaccini
    • 2.4.1. Introduction| html | pdf |
      • 2.4.1.1. The dictionary data model| html | pdf |
        • 2.4.1.1.1. Comparison with the CIF syntax data model| html | pdf |
      • 2.4.1.2. Dictionary definition languages| html | pdf |
    • 2.4.2. DDLm| html | pdf |
      • 2.4.2.1. The DDLm data model| html | pdf |
        • 2.4.2.1.1. Loop and Set categories| html | pdf |
        • 2.4.2.1.2. Category and definition hierarchy| html | pdf |
        • 2.4.2.1.3. Data-name relationships| html | pdf |
      • 2.4.2.2. The DDLm attributes| html | pdf |
        • 2.4.2.2.1. Item-level attributes| html | pdf |
        • 2.4.2.2.2. Category-level attributes| html | pdf |
        • 2.4.2.2.3. Dictionary-level attributes| html | pdf |
        • 2.4.2.2.4. Importation| html | pdf |
      • 2.4.2.3. Dictionary types| html | pdf |
      • 2.4.2.4. Stylistic considerations| html | pdf |
      • 2.4.2.5. A note on estimated standard deviations| html | pdf |
        I. David Brown
      • 2.4.2.6. Style guide for DDLm dictionaries| html | pdf |
        James R. Hester, Antanas Vaitkus and Brian McMahon
        • 2.4.2.6.1. Terminology| html | pdf |
        • 2.4.2.6.2. Lines and padding| html | pdf |
        • 2.4.2.6.3. Value formatting| html | pdf |
          • 2.4.2.6.3.1. Text strings| html | pdf |
          • 2.4.2.6.3.2. Lists| html | pdf |
          • 2.4.2.6.3.3. Tables| html | pdf |
          • 2.4.2.6.3.4. Multi-line compound object| html | pdf |
          • 2.4.2.6.3.5. Enumeration ranges| html | pdf |
            • 2.4.2.6.3.5.1. Integer ranges| html | pdf |
            • 2.4.2.6.3.5.2. Real-number ranges| html | pdf |
        • 2.4.2.6.4. Data items| html | pdf |
          • 2.4.2.6.4.1. Attribute–value pairs| html | pdf |
          • 2.4.2.6.4.2. Loops| html | pdf |
        • 2.4.2.6.5. Ordering| html | pdf |
          • 2.4.2.6.5.1. Front matter and definitions| html | pdf |
          • 2.4.2.6.5.2. Layout of non-save-frame information| html | pdf |
          • 2.4.2.6.5.3. Definition layout| html | pdf |
        • 2.4.2.6.6. Naming convention| html | pdf |
        • 2.4.2.6.7. Known implementations| html | pdf |
      • 2.4.2.7. History and maintenance| html | pdf |
    • 2.4.3. DDL2| html | pdf |
      John D. Westbrook, Helen M. Berman and Sydney R. Hall
      • 2.4.3.1. History of DDL2 development| html | pdf |
      • 2.4.3.2. Overview of the elements of DDL2| html | pdf |
      • 2.4.3.3. DDL2 organization| html | pdf |
      • 2.4.3.4. DDL2 dictionary applications| html | pdf |
      • 2.4.3.5. Detailed DDL2 specifications| html | pdf |
        • 2.4.3.5.1. DDL2 definitions describing data items| html | pdf |
          • 2.4.3.5.1.1. ITEM| html | pdf |
          • 2.4.3.5.1.2. ITEM_ALIASES| html | pdf |
          • 2.4.3.5.1.3. PDBX_ITEM_CONTEXT| html | pdf |
          • 2.4.3.5.1.4. ITEM_DEFAULT| html | pdf |
          • 2.4.3.5.1.5. ITEM_DEPENDENT| html | pdf |
          • 2.4.3.5.1.6. ITEM_DESCRIPTION| html | pdf |
          • 2.4.3.5.1.7. ITEM_ENUMERATION| html | pdf |
          • 2.4.3.5.1.8. ITEM_EXAMPLES| html | pdf |
          • 2.4.3.5.1.9. ITEM_LINKED| html | pdf |
          • 2.4.3.5.1.10. PDBX_ITEM_LINKED_GROUP and PDBX_ITEM_LINKED_GROUP_LIST| html | pdf |
          • 2.4.3.5.1.11. ITEM_METHODS| html | pdf |
          • 2.4.3.5.1.12. ITEM_RANGE| html | pdf |
          • 2.4.3.5.1.13. ITEM_RELATED| html | pdf |
          • 2.4.3.5.1.14. ITEM_STRUCTURE| html | pdf |
          • 2.4.3.5.1.15. ITEM_STRUCTURE_LIST| html | pdf |
          • 2.4.3.5.1.16. ITEM_SUB_CATEGORY| html | pdf |
          • 2.4.3.5.1.17. ITEM_TYPE| html | pdf |
          • 2.4.3.5.1.18. ITEM_TYPE_CONDITIONS| html | pdf |
          • 2.4.3.5.1.19. ITEM_TYPE_LIST| html | pdf |
          • 2.4.3.5.1.20. ITEM_UNITS| html | pdf |
          • 2.4.3.5.1.21. ITEM_UNITS_CONVERSION| html | pdf |
          • 2.4.3.5.1.22. ITEM_UNITS_LIST| html | pdf |
          • 2.4.3.5.1.23. PDBX_ITEM_VALUE_CONDITION and PDBX_ITEM_VALUE_CONDITION_LIST| html | pdf |
        • 2.4.3.5.2. DDL definitions describing categories| html | pdf |
          • 2.4.3.5.2.1. CATEGORY| html | pdf |
          • 2.4.3.5.2.2. PDBX_CATEGORY_CONTEXT| html | pdf |
          • 2.4.3.5.2.3. CATEGORY_EXAMPLES| html | pdf |
          • 2.4.3.5.2.4. CATEGORY_GROUP and CATEGORY_GROUP_LIST| html | pdf |
          • 2.4.3.5.2.5. CATEGORY_KEY| html | pdf |
          • 2.4.3.5.2.6. CATEGORY_METHODS| html | pdf |
          • 2.4.3.5.2.7. SUB_CATEGORY| html | pdf |
          • 2.4.3.5.2.8. SUB_CATEGORY_EXAMPLES| html | pdf |
          • 2.4.3.5.2.9. SUB_CATEGORY_METHODS| html | pdf |
        • 2.4.3.5.3. DDL2 definitions describing methods| html | pdf |
          • 2.4.3.5.3.1. METHOD_LIST| html | pdf |
        • 2.4.3.5.4. DDL2 definitions describing dictionaries and data blocks| html | pdf |
          • 2.4.3.5.4.1. DATABLOCK| html | pdf |
          • 2.4.3.5.4.2. DATABLOCK_METHODS| html | pdf |
          • 2.4.3.5.4.3. DICTIONARY| html | pdf |
          • 2.4.3.5.4.4. DICTIONARY_HISTORY| html | pdf |
          • 2.4.3.5.4.5. PDBX_INCLUDE_DICTIONARY, PDBX_INCLUDE_CATEGORY and PDBX_INCLUDE_ITEM| html | pdf |
          • 2.4.3.5.4.6. PDBX_DICTIONARY_COMPONENT and PDBX_DICTIONARY_COMPONENT_HISTORY| html | pdf |
    • References | html | pdf |
    • Figures
      • Fig. 2.4.2.1. Example of DDLm dictionary structure using an extract from a development version of the twinning dictionary (Chapter 3.5[link] )| html | pdf |
      • Fig. 2.4.2.2. A definition for _diffrn_source.device showing use of the most common attributes| html | pdf |
      • Fig. 2.4.2.3. Examples of the use of default enumerations| html | pdf |
      • Fig. 2.4.2.4. A category definition for ATOM_SITE showing use of the most common category-level attributes| html | pdf |
      • Fig. 2.4.2.5. Dictionary-level attributes as they appear in a development version of the restraints dictionary| html | pdf |
      • Fig. 2.4.2.6. Use of the DICTIONARY_VALID category within the DDLm dictionary, demonstrating which data names and categories (in capitals) may or may not appear in dictionary-level, category or item definitions| html | pdf |
      • Fig. 2.4.2.7. Different import descriptions| html | pdf |
      • Fig. 2.4.2.8. Importing in `Contents' mode| html | pdf |
      • Fig. 2.4.3.1. DDL2 attributes specifying core item-level information (a) and (b), linked item groups (c), item value conditions (d), and conditionally linked items (e)| html | pdf |
      • Fig. 2.4.3.2. DDL2 attributes describing category, subcategory and category group information| html | pdf |
      • Fig. 2.4.3.3. DDL2 attributes describing dictionary and data-block information (a), dictionary composition (b), and dictionary component version history (c)| html | pdf |
    • Tables
      • Table 2.4.1.1. Comparison between CIF terms and equivalent relational terminology| html | pdf |
      • Table 2.4.2.1. Common attributes used in item definitions| html | pdf |
      • Table 2.4.2.2. Deriving DDLm types from CIF data values| html | pdf |
      • Table 2.4.2.3. Attributes used in category definitions| html | pdf |
      • Table 2.4.2.4. Attributes used for dictionary description| html | pdf |
      • Table 2.4.2.5. Values used in the style specification| html | pdf |
      • Table 2.4.3.1. Relationships defined by _item_related.function_code| html | pdf |