The formula layerStep 3 of 17 of the InChI walkthrough. The first layer is the molecular formula in Hill order: carbon first, hydrogen second, then everything else alphabetically. Hydrogens are counted across the whole structure, including the ones that will later turn out to be mobile. This is the one layer you can write without numbering anything.It opens on CN1C=NC2=C1C(=O)N(C)C(=O)N2C, 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.

Convert — a structure in, an InChI out

Batch — a whole CSV, XLSX or SDF file

Tutorial — how an InChI is derived

Exercises — write the layers yourself

Cheatsheet — every layer in a table

Tests — the IUPAC regression corpora

Download — take the engine away

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