On Narumi-Katayama indices of molecular graphs and its modified version

Abstract

Let G be a simple connected molecular graph in chemical graph theory, then its vertices correspond to the atoms and the edges to the bonds. Chemical graph theory is an important branch of graph theory, such that there exist many topological indices in it. The Narumi-Katayama index and its modified version of a graph G, denoted by NK(G) and NK*(G) are equal to the product of the degrees of the vertices of G. In this paper we compute the Narumi-Katayama index and its modified version for some important class of carbon nanotube networks, dominating oxide network, dominating silicate network and regular triangulene oxide network.