A Lower Bound of the General Randi´ c Index of Chemical Graphs

For any arbitrary real number α, the general Randic index Rα(G) of a graph G, is defined as ∑ uv∈E(G)(d(u)d(v)) α, where uv is an edge of G, d(u) is the degree of vertex u in G. In this paper we characterize the structures of extremal chemical trees with the minimum general Randic index and give the structure of chemical graphs with minimum general Randic index, for −1 < α < 0.