Simplified molecular input line entry specification

A somewhat dilferent way to define a molecule is as a simplified molecular input line entry specification (SMILES) structure. It is a way of writing a single text string that defines the atoms and connectivity. It does not define the exact bond lengths, and so forth. Valid SMILES structures for ethane are CC, C2, and H3C-CH3. SMILES is used because it is a very convenient way to describe molecular geometry when large databases of compounds must be maintained. There is also a very minimal version for organic molecules called SSMILES. 

SMILES (simplified molecular-input line-entry specification) a way of specifying a molecular formula and connectivity, but not the three-dimensional geometry... 

SMILES (for Simplified Molecular Input Line Entry Specification) notations, as a compact molecular representation [8]. 

RMSEte Root mean square error for the test set RMSEtr Root mean square error for the training set SMILES Simplified molecular input line entry specification... 

SMILES simplified molecular input line entry specification... 

Rule scripts operate on substances defined in a data file in either SMILES (simplified molecular input line entry specification) or CMP (compound) format. The conventional SMILES notation as developed by Weininger [28] provides a basic description of molecules in terms of two-dimensional chemical graphs. The CMP file format developed with the OASIS system [29] provides separate logical records for information about connectivity, three-dimensional structure, electronic structure from quantum-chemical molecular-orbital computations, as well as physicochemical and experimental toxicological data. 

Structure registration is the process of entering structural information in a centralized repository, usually a structure database. These repositories serve as a pool for providing structure information that has been created in other departments of a company. Structure databases are set up according to the individual needs of a department or company. They consist of a common representation of a structure in a standardized file format, such as MolFile, SDF, reaction (RXN) (MDL), JCAMP (International Union of Pure and Applied Chemistry), or simplified molecular input line entry specification. Any additional data can be stored with the structure depending on the context typical examples are structure properties, reaction conditions, and literature references. 

SMILES Simplified Molecular Input Line Entry Specification... 

SMILES is an acronym for Simplified Molecular Input Line Entry Specification. The algorithm is a universal nomenclature. It was developed in 1988 by Weininger [15]. Several computer programs use now the SMILES algorithm. We briefly show a few most important rules to represent chemical structures by SMILES. We definitely refer to a more detailed version that is given in the Internet [16]. 

Example Functional Group Names and General Formulas in Simplified Molecular Input Line Entry Specification or SMILES Format... 

The introduction of the G-SIMS approach, applied by itself or in combination with Fragmentation Pathway Mapping (FPM) and Simplified Molecular Input Line Entry Specification (SMILES), has, however, opened up the possibility of understanding the various fragment pathways and matching SIMS spectra collected under different analytical conditions. 

For more complex molecular spectra, particularly those collected under Static SIMS conditions, the situation becomes more complicated. In such cases, comparative analysis of spectra or even the use of the Gentle SIMS approach may be required. The original parent molecule responsible for the respective signals can also be defined when the Gentle SIMS approach is combined with the FPM along with the use of the Simplified Molecular Input Line Entry Specification algorithm. 

CAS = Chemical Abstracts Service CIP = Cahn-Ingold-Prelog system of labeling stereogenic atoms and bonds MDLI = Molecular Design Limited, Inc. MIF = molecular information file MOLFile = molecule file SEMA = stereo-chemically extended Morgan algorithm SMD = Standard Molecular Data SMILES = simplified molecular input line entry specification. 

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