The /t tetrahedral layerStep 14 of 17 of the InChI walkthrough. A stereocentre gets a tetrahedral parity. Put your eye on the hydrogen — or on the neighbour with the smallest canonical number when there is no hydrogen — and look towards the centre. If the three remaining neighbours run clockwise in increasing canonical number the parity is plus, anticlockwise is minus. Alanine has one such centre, atom 2.It opens on N[C@@H](C)C(=O)O, drawn live, so the layer under discussion changes as you change the structure.Convert a structure to its InChI and InChIKey and back, convert a whole CSV, XLSX or SDF file, learn how the identifier is derived, and practise writing its layers. The InChI engine is WebAssembly running in your browser, so the tool needs JavaScript — and nothing you open ever leaves your machine.

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