Summary
Chemical facts from the source, not from the model.
Molecular weights and identifiers are exactly the kind of number a language model will produce confidently and get slightly wrong. Routing the question to PubChem means the property in the answer is the one on record, and a SMILES string works as the query when the name is ambiguous.
What it is
A lookup against PubChem, the public chemical database. A compound can be named in words or given as a SMILES string, and what comes back is its identifiers, structure and recorded properties.
What you get
- Compound search by common or systematic name
- Compound search by SMILES, for a structure you already have in hand
- Molecular structures and the identifiers that go with them
- The chemical and physical properties PubChem records for a compound
- A cap on how many results come back, so a broad name does not flood the answer
Requirements
Python on your PATH. No account and no key — PubChem is open.
Setup effort
One command — uv tool install pubchem-mcp-server