On Unicyclic Graph with Minimal Second Atom-Bond Connectivity Index

摘要

Another version of atom-bond connectivity index was defined by Graovac and Ghorbani,and called the second atom-bond connectivity index(ABC2),which can provide convenience for molecular feature and its extreme values are the focus of study.In this paper,by fractional comparison,we give the structural properties of the extremal graphs which attain the minimal ABC2 index of unicyclic graphs of order n.