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Core CIF Dictionary version 2.3

_chemical_absolute_configuration

Name

'_chemical_absolute_configuration'

Category: chemical

Data type: char

Permitted values:

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'

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)

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