Self-defining Text Archive and Retrieval

Self-defining Text Archive and Retrieval

Developed by	Sydney R. Hall
Initial release	1991
Extended to	Crystallographic Information File, Dictionary Definition Language

The Self-Defining Text Archive and Retrieval (STAR) File, or simply the STAR File, is a text-based file format for storing structured data. It was proposed in 1991 by Sydney R. Hall. The format became widely used in molecular-structure sciences, although it is not specific to this field—it was designed as a universal approach to electronic data exchange and archiving.

One characteristic feature of the STAR File format is that data names (keys in key-value pairs) start with the underscore. They are separated from data values only by white space, for example:

_format "STAR File"
_first_published 1991

The format was designed to provide a concise syntax for tabular data. The construct for this is called loop. Loops start with the loop_ keyword followed by names corresponding to columns and then by values.

loop_
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
_geom_bond_distance
O1 C8 1.301(3)
O1 Na1 2.161(2)
O2 C36 1.425(4)
O2 C39 1.425(4)
O2 Na1 2.514(3)
O3 C31 1.421(4)
# ...

Using a "Dictionary Definition Language" file, itself a STAR File, STAR sub-formats can be defined for particular use cases. One notable STAR-based format is the Crystallographic Information File format.

The "STAR FILE" name is a registered trade mark of the International Union of Crystallography .

See also

• Hall, Sydney R. (1991). "The STAR file: a new format for electronic data transfer and archiving". J. Chem. Inf. Comput. Sci. 31 (2): 326–333. doi:10.1021/ci00002a020.
• Hall, Sydney R.; Spadaccini, Nick (1994). "The STAR File: detailed specifications". J. Chem. Inf. Comput. Sci. 34 (3): 505–508. doi:10.1021/ci00019a005.
• Spadaccini, Nick; Hall, Sydney R. (2012). "Extensions to the STAR File Syntax". J. Chem. Inf. Model. 52 (8): 1901–1906. doi:10.1021/ci300074v.