Description of cyclic and branched-acyclic hydrocarbons by variants of the hyper-Wiener index

Abstract The hyper-Wiener index R was originally defined for acyclic structures. Four different techniques have been proposed so far in order to extend this definition for cycle-containing structures. A computational method for the “delete path” version of R is presented for molecules containing a single cycle and a side branch. Formulas for simple cycles are derived for the “delete path” and for the “count path” versions of R. The variants of the hyper-Wiener number are compared with respect to their use in quantitative structure-property relationships.