Graph theory, electronic structures and reaction mechanisms

An attempt is made to describe the electronic structure of molecules and supermolecules in terms of graphs. Bearing in mind that the map of localized orbital centroids is a line graph, the localization process can be seen as a way of generating an electronic description of molecules. A set of Lewis-type rules is defined which is capable of predicting chemical graphs for molecules, as well as for radicals and transition structures. Considering the electronic change which occurs along a reaction pathway, `oriented transformation graphs' can be written which summarize the electronic reorganization. This analysis suggests a definition for the least change of electronic structure during a chemical process.Anglai