Atom-Bond Sum-Connectivity Index of Unicyclic Graphs and Some Applications

Abstract

The atom-bond sum-connectivity (ABS) index is a recently introduced variant of three earlier much studied graph-based molecular descriptors: connectivity (Randi), atom-bond connectivity, and sum-connectivity indices. In this paper, the graphs with minimum, second-minimum, maximum, and second-maximum values of the ABS index are determined over the class of connected unicyclic graphs with a fixed order. Possible chemical applications of the ABS index are also investigated on particular sets of chemical graphs.