| Allowed Value | Details | 
|---|---|
| ad | absolute configuration established by anomalous-dispersion effects in diffraction measurements on the crystal | 
| rm | absolute configuration established by the structure determination of a compound containing a chiral reference molecule of known absolute configuration | 
| 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 | 
| Allowed Value | Details | 
|---|---|
| ad | absolute configuration established by anomalous-dispersion effects in diffraction measurements on the crystal | 
| rm | absolute configuration established by the structure determination of a compound containing a chiral reference molecule of known absolute configuration | 
| 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 |