Crystallographic Information Framework

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Index

Restraints dictionary version 1.0

Category RESTR_RIGID_BODY

Name:
'_restr_rigid_body_[]'

Definition:

   Items in this category list the atoms defining one or
   more bodies that are constrained to be rigid in the final
   refinement.  This is done by listing the atom-site label
   and symmetry operation for each atom in each rigid body.

   Since rigid bodies are only constrained, not restrained,
   the rigid body is adequately defined by the refined coordinate
   in the atom_site list. A second category,
   restr_rigid_body_class, permits a description
   of each rigid body to be given in a *_details item.

Example:

Example 1. The first rigid body contains C1, C2, C3 and C4, the second rigid body contains C3, C4, C5 and C6. The bond between C3 and C4 is common to both rigid bodies. 
 
    loop_
    _restr_rigid_body_id
    _restr_rigid_body_atom_site_label
    _restr_rigid_body_site_symmetry
    _restr_rigid_body_class_id
    _restr_rigid_body_details
      1 C1 1_555  1  ?
      2 C2 1_555  1  ?
      3 C3 1_555  1  'C3 is a hinge atom'
      4 C4 1_555  1  'C4 is a hinge atom'
      5 C3 1_555  2  ?
      6 C4 1_555  2  ?
      7 C5 2_555  2  ?
      8 C6 1_555  2  ?


Type: null

Category: category_overview


International Tables for Crystallography

Volume G: Definition and exchange of crystallographic data

First online edition (2006)

Edited by S. R. Hall and B. McMahon

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