Chemical graph theory is the topology branch of mathematical chemistry which applies graph theory to mathematical modelling of chemical phenomena.[1] The pioneers of the chemical graph theory are Alexandru Balaban, Ivan Gutman, Haruo Hosoya, Milan Randić and Nenad Trinajstić.[2] In 1988, it was reported that several hundred researchers worked in this area producing about 500 articles annually. A number of monographs have been written in the area, including the two-volume comprehensive text by Trinajstic, Chemical Graph Theory, that summarized the field up to mid-1980s.[3]
The adherents of the theory maintain that the properties of a chemical graph, i.e., a graph-theoretical representation of a molecule gives valuable insights into the chemical phenomena. The opponents contend that graphs play only a fringe role in chemical research.[4] One variant of the theory is the representation of materials as infinite Euclidean graphs, particularly crystals by periodic graphs.