on the bicyclic graphs with minimum reduced reciprocal randic index

The reduced reciprocal randić (rrr) index is a molecular structure descriptor (or more precisely, a topological index), which is useful for predicting the standard enthalpy of formation and normal boiling point of isomeric octanes. in this paper, a mathematical aspect of rrr index is explored, or more specifically, the graph(s) having minimum rrr index is/are identified from the collection of all n–vertex connected bicyclic graphs for n ≥ 5. as a consequence, the best possible lower bound on the rrr index, for n–vertex connected bicyclic graphs is obtained when n ≥ 5.