Original Articles: 2016 Vol: 8 Issue: 4
The Second Zagreb Eccentricity Index of Polycyclic Aromatic Hydrocarbons PAHk
Abstract
A topological index is a real number related to a molecular graph, it does not rely on the labeling or pictorial
representation of a graph. The first and second Zagreb indices are defined as ( ) ( ) ( )
2
1 v V G
M G d v Î =Σ and
( ) ( ) ( ) 2 uv E(G)
M G d u d v Î =Σ , respectively. Recently, Nilanjan introduced the first and second Zagreb
eccentricity indices as ( ) ( ) ( )
2
1 v V G
E G e v Î Õ =Õ and ( ) ( ) ( ) 2 uv E(G)
E G e u e v Î Õ =Õ ´ . In this paper,
we compute the first and second Zagreb indices of Polycyclic Aromatic Hydrocarbons (PAHk).