ANGULAR GEOMETRIC INDICES

Abstract

Topological indices (TIs) are important tools for analyzing the nature of biological and chemical networks. There are five types of TIs: Degree based TIs, distance based TIs, eigenvalue based TIs, matching based TIs and mixed TIs. Degree based TIs are defined by using classical degree concept in graph theory. The Zagreb and Randi´ c TIs are the most used TIs in literature. An gular geometric graph, geometric degree and angle degree notions have been defined recently in graph theory. The angles between the atoms (vertices) and bonds (edges) are important in biology and chemistry but are not important in graph theory. In this respect, angular geometric graphs, in which the angles within this graph are important and unalterable, represent more realistic model for biological and chemical networks and molecular structures. In this study, we firstly defined angular geometric Zagreb and angular geometric Randic TIs by using geometric degree notion. We compare these novel TIs with their classical degree based counterparts TIs for the prediction of some chemical properties of octanes. It is shown that the newly defined an- gular geometric indices do not give a higher correlation coefficients than their classical counterparts .