What do the stereochemical flags do?
1. SAbs, SRel, SRac are three mutually exclusive statements about the overall chirality of the compound: • SAbs: the compound is a single enantiomer where the absolute configuration is known at all of the known centres in the /t layer. There may also be unknown centres but at least one must be absolutely known. The flag /s1 is set automatically. The /m flag will always be present (it is always absent in SRel, and SRac). Note that two enantiomeric InChIs will have identical /t layers but will differ by having /m0 or /m1. The /m1 configuration is logically identical to the /m0 configuration with all signs changed. Note that /m forces /s1 but this flag is still a required part of the InChI. SAbs is the default, so beware that leaving this altered will imply that the compound is of known absolute configuration If a mirror image of a structure is identical to the structure then no /s1 or /m will be added. The same will happen in case of SRel or SRac. For example: • SRel: the compound is a s
