The Multiplicative Version of the Wiener Index

The classical Wiener index, W(G), is equal to the sum of the distances between all pairs of vertexes of a (molecular) graph, G. We now consider a related topological index, π(G), equal to the product of distances between all pairs of vertexes of G. The basic properties of the π index are established and its possible physicochemical applications examined. In the case of alkanes, π and W are highly correlated; a slightly curvilinear correlation exists between ln π and W.