Check stereochemistry, properties, names and spin

Open stereochemistry.vsk. It contains a specified lactic-acid stereocentre, an E-configured difluoroethene, isotopically labelled methane, ammonium and a methyl radical. This is a properties worksheet, not a reaction.

A real sketch containing a wedge-bearing lactic acid, E difluoroethene, carbon-13 methane, ammonium and methyl radical.

Wedges, double-bond geometry, isotope labels, formal charge and radicals carry different information. Check each independently.

Draw and inspect

  1. Open lactic-acid.vsk. Use the bond palette’s wedge and hashed bond tools to specify a tetrahedral centre. Switching a wedge can change the stereoisomer; Undo restores the example.

  2. Read the formula, average and monoisotopic masses, SMILES, InChI and InChIKey in the species card. The formula is C3H6O3. A matching formula alone cannot distinguish its stereoisomers.

  3. Enter 1 in Compound number to label the species. Draw short numbers beneath molecules or condition text beside arrows using the T tool when those labels should also be visible on the canvas.

  4. Compare the E double bond and isotope-labelled methane in the worksheet. Atom labels and charge tools change the structure; free text is an annotation.

Lactic acid drawn with specified stereochemistry beside its formula, masses and identifiers in the properties panel.

The structure’s identity comes from its drawing. The name line separately reports whether a name was checked, suggested, set by the user or unavailable.

Names are checked, not assumed

If the optional vibe-qc naming engine is present, a verified name maps back to the structure. An unchecked suggestion is explicitly labelled; a mismatched name is withheld. Without the engine, the card says so. Importing a name and generating one are limited to the engine’s supported chemistry. For a command-line check:

vibe-sketch name 'C=C'
vibe-sketch info stereochemistry.vsk --json
vibe-sketch info stereochemistry.vsk --json --no-names

name exits 3 for an unverified/refused name, or 1 with an install hint when the engine is unavailable; read its explanation. To set your own name, use the SDK’s Name model, REST species patch, or MCP set_species. The browser displays that name with a yours badge. It is not presented as an engine-verified identification. The REST/MCP examples set a name and compound number explicitly.

Set multiplicity with the electron count in mind

Open methyl-radical.vsk. [CH3] is neutral with multiplicity 2. [NH4+] in the worksheet has charge +1 and multiplicity 1. Charge is derived from the atoms’ formal charges; Multiplicity is editable in the species card.

Methyl radical in the actual app with CH3 formula, neutral charge and multiplicity 2.

A radical example: the app proposes a doublet and does not invent an IUPAC name.

Try setting the methyl radical’s multiplicity to 1. The incompatible electron parity is refused; restore 2. A parity-compatible value is not proof of the physical ground state. Metal centres need an informed explicit choice.

Save the worksheet and inspect it with vibe-sketch validate. Then follow cleanup and 3D: the embedder checks specified R/S and E/Z against the generated coordinates and reports unspecified stereo.