International Tables for Crystallography

Volume G: Definition and exchange of crystallographic data

First online edition (2006)

Edited by S. R. Hall and B. McMahon
[International Tables Vol. G] contents
indexes
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CIF dictionaries

Describes CIF, the data exchange standard of crystallography. Provides: information for scientists who wish to record or use the results of a single-crystal or powder diffraction experiment; the data ontology necessary for designing interoperable computer applications; accompanying software including machine-readable CIF dictionaries, libraries and utility programs.

An essential guide and reference to CIF for programmers, data managers handling crystal-structure information and practising crystallographers.

Index

Core dictionary (coreCIF) version 2.4.2

_symmetry_equiv_pos_as_xyz

Name:
'_symmetry_equiv_pos_as_xyz'

This definition has been superseded and is retained here only for archival purposes. Use instead '_space_group_symop_operation_xyz'

Definition:

   Symmetry-equivalent position in the 'xyz' representation. Except
   for the space group P1, these data will be repeated in a loop.
   The format of the data item is as per International Tables for
   Crystallography Vol. A. (2002). All equivalent positions should
   be entered, including those for lattice centring and a centre of
   symmetry, if present.

   In order for the defaults to work correctly, the identity
   operation should have _space_group_symop_id or
   _symmetry_equiv_pos_site_id set to 1, and
   _space_group_symop_operation_xyz or
   _symmetry_equiv_pos_as_xyz set to x,y,z; 
   i.e. the operation labelled 1 should be the identity
   operation.

Example:

-y+x,-y,1/3+z

May appear in list

Related item:
Enumeration default: x,y,z

Type: char

Category: symmetry_equiv