DDL specifications

The datanames appearing in CIF files are defined in plain text dictionaries. These are highly structured documents written in a controlled language to make them accessible to both people and computers. The language used in the dictionaries is known as a Dictionary Definition Language (DDL).

New CIF dictionaries are written in either DDL2 and DDLm. Earlier dictionaries were written in DDL1.  The DDL1 dictionaries are being gradually replaced by DDLm equivalents.  Further resources are available here.

See also:

  • (DDL1) Hall, Sydney R. & Cook, A. F. P. (1995), J. Chem. Inf. Comput. Sci., 35, 819-825
  • (DDLm) Spadaccini, N. and Hall, S.R. (2012), J. Chem. Inf. Model, 52(8), 1907-1916