CHEMICS software

The most important feature of editing software is the option to save the structure in standard file formats which contain information about the structure (e,g., Mol-filc. PDB-filc). Most of these file formats arc ASCII text files (which can be viewed in simple text editors) and cover international standardized and normalized specifications of the molecule, such as atom and bond types or connectivities (CT) (see Section 2,4). Thus, with these files, the structure can be exchanged between different programs. Furthermore, they can seiwe as input files to other chemical software, e.g, to calculate 3D structures or molecular properties. 

The popularity of problem-solving computer programs had been low, and thus also the general acceptance of such computer programs has been slugish. With the availability of low-cost/high-power PCs and new chemical software for these machines, the use of computers in chemical research and education will, finally, take off. 

Anonymous, Annual Report of Chemical Software, 1994 ed., The Chemical Software Society of Japan, Sabae, Japan, 1994. 

At the time of writing of this chapter, InChIKey is a very new format. However, once it starts to gain support in chemical software and online databases, it will have the potential to replace conventional registry numbers and provide a standardized, easy to use chemical identifier that is based solely on the molecular structure. 

Linear formats are usually not good candidates for primary data storage, simply because they do not contain the molecular geometry. Therefore, it is advisable to use one of the file-based formats for this purpose—either Molfile or CML. These are very similar in their capabilities and have good support in various chemical software packages, with Molfile usually having slightly smaller files and even wider support than CML. 

The development of algorithms for the handling of chemical structures and data, and the application of artificial intelligence to property prediction, etc., led to the emergence of companies specialising in chemical software applications, now known as chem(o)informatics. Ideally such enterprises should couple with large dictionary databases. 

Recent progress in the development of quantum chemical computational methods [1] and quantum chemical software provided a user-friendly tool to chemists, helping them to explain many problems met in a chemical laboratory. The most frequent task is to determine the optimum structure of molecules, relative energies of reaction components, heats of formation, vibrational frequencies, energies of activation and energies of ionization. In all these cases, a standard theoretical approach is to perform first... 

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