Dynamic Representation of Quantum Chemical Results Using Computer-Graphics - Molecular-Rearrangements, Art or Science

An interactive computer graphics equipment is used as an output device for representing the results of quantum chemical calculations. The advantages of such displays are illustrated by the description of several applications: (i) interactive visualization of molecular properties and (ii) dynamic representation of unimolecular rearrangements. Several examples are chosen among the latter group of applications: reversible formation of cyclobutene from 1,3-butadiene, intramolecular migration of a methyl group over an allyl substrate, and pseudo-rotation of a seven-membered heterocyclic compound. It is shown that the 3D representation of reaction paths is generally an involved task since, as the geometrical data base is most often incomplete, it is necessary to find a middle ground between chemically reasonable and aesthetically pleasant pictures, thus leading to a technique which lies somewhere in between art and science.