Simplified Molecular Input Line Entry System

The Simplified Molecular Input Line Entry System (SMILES) is a specification in the form of a line notation for describing the structure of chemical species using short ASCIIstrings. SMILES strings can be imported by most for conversion back into two-dimensional drawings or three-dimensional models of the molecules.

The original SMILES specification was initiated in the 1980s. It has since been modified and extended. In 2007, an open standard called OpenSMILES was developed in the open source chemistry community to harmonize the different dialects.