smi
What is a .smi file?
chemical/x-daylight-smiles
A .smi file holds SMILES strings — a line notation that encodes a molecular graph as text. Atoms are written as element symbols, aromatic atoms in lower case, bonds as `-`, `=`, `#`, branches in parentheses, and rings as matching digit labels, with stereochemistry expressed by `/`, `\\`, and `@` markers. Files typically carry one SMILES per line with an optional whitespace-separated identifier, and a canonical SMILES is a unique string for a given structure.
How to use a .smi file
Use an example .smi file to test SMILES parsers, canonicalisers, and structure-search tooling, verifying ring-closure and aromaticity handling, stereochemistry round-tripping, and that an invalid string is rejected rather than partially parsed.
Download example .smi files
- Ethanol — SMILES String (.smi)Ethanol as a single tab-delimited SMILES record, the most compressed member of this family: three heavy atoms with every hydrogen implicit and no geometry whatsoever. Round-tripping molfile to SMILES and back is the classic lossy conversion, and this pair is the reference for it.
- SMILES Library — Ten Structures Including Aromatics and Salts (.smi)Ten tab-delimited SMILES covering the notation features that trip parsers: lowercase aromatic atoms, ring-closure digits, branch parentheses, explicit charges in brackets and a dot-disconnected salt. Every structure is small enough to verify by hand.