Interpretation of organic chemical formulas by computer

Over the last few years, a frequently discussed problem in the area of chemical information systems has been the need for some means by which chemists could communicate with the system in terms of their normal chemical language, the structural formula, rather than requiring them to use special, machine-oriented notations. The Walter Reed Army Institute of Research (WRAIR), as part of its Chemical Structures Storage and Retrieval System, has developed an economical and effective computer program to analyze structural formulas as normally written by chemists, producing as output a detailed description, in machine-oriented format, of the atoms in the molecule and their connections to each other. In principle, any trained chemist can prepare compounds for entry in the system master file, or questions for searching it, without any special training in the WRAIR system. The program is now being used in daily operations and is, we believe, the only operational program capable of performing this function without major restrictions on the formulas which can be accepted. As a special case of the general problem of the man-machine interface, the program may well be of interest outside the chemical field, particularly since many of the techniques used have no essential relation to chemistry.