### 16.5. Does the InChI Software ignore stereochemistry if a coordinate-less (“0D”) input file in MOL/SDF format is used? 

Yes. 

In principle, it would try to recognize tetrahedral stereo expressed through wedge bonds. However, no way exists to recognize stereochemistry of double bonds in the absence of atomic coordinates, using MOL format. Therefore, all the stereochemistry is deliberately ignored, as a matter of decision. (Otherwise one would get different InChI stereo layers for 3D and 0D structures of the same compound.) However, the InChI API library accepts input atom and bond parities, which may be derived by the calling software from, for example, SMILES.