mcp-molecules
Atoms and molecules for the artificial minds — trustworthy chemistry tools, computed for real and backed by authoritative data.
Atoms combine into molecules, and a language model asked about them should not have to recall facts from memory; it should compute answers it can trust. mcp-molecules is a growing toolbox for working with chemical elements and molecules — offline, deterministic, and backed by authoritative sources such as the NIST Atomic Weights and Isotopic Compositions database.
For example, it can already take a chemical formula and return its molecular weight: ask "what does C₆H₁₂O₆ weigh?" and it parses the formula, looks every element up in NIST data, and computes the molar mass rather than guessing it. More molecule-oriented tools are planned.
You can ask things like:
- "What does a mole of glucose weigh?" — resolves the name to C₆H₁₂O₆ and computes the molar mass.
- "How much of Fe₂(SO₄)₃'s mass is iron?" — per-element percent composition.
- "What's the molar mass of caffeine, with uncertainty?" — propagates the NIST standard uncertainties.
- "What does the mass spectrum of chloroform look like?" — the natural chlorine isotope pattern (the M, M+2, M+4 … peaks).
- "What's the [M+H]⁺ m/z for caffeine?" — the protonated-ion mass.
- "Which compound has the formula C₉H₈O₄?" — formula → name (aspirin, among its isomers).
- "What are the isomers of C₂H₆O?" — one formula, several names (ethanol and dimethyl ether).
