Simplified Molecular Input Line Entry Specification (SMILES) is a straightforward coding system for unambiguously describing molecular structures using alpha-numeric character strings in which atoms are represented by their atomic symbols and bonds are only represented when they are multiple in the same way as written according to IUPAC standards. Branches are specified in parentheses and/or square brackets. Most molecular editors can interpret these SMILES codes for conversion into two-or three-dimensional graphical molecular models . There is a form of canonical representation, which is the one used in computational studies since it "guarantees to have unique molecules," facilitating rapid data mining in chemical library databases. SMILES is not only used for the representation of molecular models but also for performing similarity searches, in which a comparison of the physicochemical properties of molecules is carried out. SMILES is, therefore, useful in drug design studies based on physicochemical properties , molecular fingerprint , chemical space , and molecular scaffold . Weininger, A., and Weininger, D. developed the original SMILES specification in the late 1980s and early 1990s . In 2007, an open standard called "OpenSMILES" was developed by the open-source chemistry community.