Computer software, nomenclature

We close this section with one more note on careful nomenclature. A code renders a model into a set of instructions that can be understood by a digital computer. Thus, if one applies a particular model, let us say the molecular mechanics model called MM3 (which will be described in the next chapter) to a particular problem, say the energy of chair cyclohexane, the results should be completely independent of which code one employs to carry out the calculation. If two pieces of software (let s call them MyProg and YourProg) differ by more than the numerical noise that can arise because of different round-off conventions with different computer chips (or having set different tolerances for what constitutes a converged calculation) then one (or both ) of those pieces of software is incorrect. In colloquial tenns, there is a bug in the incorrect code(s). 

The computer translation of systematic chemical nomenclature into chemical structures is now possible. At least three groups have software which demonstrates this. Chemical Abstracts Service has for a long time used software running on mainframe computers to translate names in its style of nomenclature into connection tables. More recently, the Beilstein Institute has developed the VICA name interpreter for an IBM 3090 mainframe. This translates with a high success rate a wide range of names into a connection table using a dictionary of some 3000 name fragments. ... 

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