Crystallographic Information Framework

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Index

Core dictionary (coreCIF) version 2.4.5

_chemical_absolute_configuration

Name:
'_chemical_absolute_configuration'

Definition:

   Necessary conditions for the assignment of
   _chemical_absolute_configuration are given by H. D. Flack and
   G. Bernardinelli (1999, 2000).

   Ref: Flack, H. D. & Bernardinelli, G. (1999). Acta Cryst. A55,
           908-915. (http://www.iucr.org/paper?sh0129)
        Flack, H. D. & Bernardinelli, G. (2000). J. Appl. Cryst.
           33, 1143-1148. (http://www.iucr.org/paper?ks0021)


The data value must be one of the following:


rm 		Absolute configuration established by the structure determination of a compound containing a chiral reference molecule of known absolute configuration.

ad 		Absolute configuration established by anomalous-dispersion effects in diffraction measurements on the crystal.

rmad 		Absolute configuration established by the structure determination of a compound containing a chiral reference molecule of known absolute configuration and confirmed by anomalous-dispersion effects in diffraction measurements on the crystal.

syn 		Absolute configuration has not been established by anomalous-dispersion effects in diffraction measurements on the crystal. The enantiomer has been assigned by reference to an unchanging chiral centre in the synthetic procedure.

unk 		Absolute configuration is unknown, there being no firm chemical evidence for its assignment to hand and it having not been established by anomalous-dispersion effects in diffraction measurements on the crystal. An arbitrary choice of enantiomer has been made.

. 		Inapplicable.

Type: char

Category: chemical


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.