Molecular Orbital Calculations Using Chemical Graph Theory

Using a functional group-like approach, one can extract a considerable amount of chemical information from a polyene molecular structure without computer intensive calculations. Jerry Ray Dias presents Huckel molecular orbital theory of polyene molecules differently from conventional textbooks. His treatment uses discrete mathematical methods on elementary substructures at an introductory level with numerous practical examples. Elementary substructures are shown to include bonds, functional groups, embedding fragments, Sachs graphs, Ulam subgraphs, irreducible subgraphs, etc. By studying elementary substructures, one can gain insight into the additive and constantive component properties of large molecules. This short treatise also contains select eigenvalues for well over 2000 molecules in compact form.