From the connectivity index to various Randić-type descriptors

Abstract

The Randić index was proposed by Randić in 1975 and has been widely studied in different areas. We briefly review the Randić index and various Randić-type descriptors from 1975 to date, including higher-order Randić indices, zeroth order Randić indices, \(D-L-S\) generalization, sum-connectivity indices, geometric-arithmetic indices, harmonic index, atom-bond connectivity index, Balaban index, Randić matrix, Randić spectrum, Randić energy, etc. We also point out some important applications of the various Randić-type indices.