Wiener−Hosoya Index A Novel Graph Theoretical Molecular Descriptor

We describe the construction of a novel molecular descriptor, called the Wiener-Hosoya index, in view of its structural relationship to both the Wiener number W and the Hosoya topological index Z. It is shown that this index has a smaller degeneracy than many simple topological indices, including W, Z, and the connectivity index chi. In a way the index can be viewed as a particular generalization of the Wiener number.