SMILES

The smiles file extension is related to SMILES, a simple yet comprehensive chemical language in which molecules and reactions can be specified using ASCII characters representing atom and bond symbols. SMILES contains the same information as is found in an extended connection table but with several advantages.

A SMILES string is human understandable, very compact, and if canonicalized represents a unique string that can be used as a universal identifier for a specific chemical structure. In addition, a chemically correct and comprehensible depiction can be made from any SMILES string symbolizing either a molecule or reaction.

SMILES development was initiated by David Weininger in the late 1980s using the concept of a graph with nodes as atoms and edges as bonds to represent a molecule. Parentheses are used to indicate branching points and numeric labels designate ring connection points. The basic SMILES grammar also includes as well as isotopic information, configuration about double bonds, and chirality leading to what is known as isomeric SMILES.

MIME types:
chemical/x-daylight-smiles
chemical/x-x-daylight-smiles