Recently, nanostructures have opened new dimensions in industry, electronics, and pharmaceutical and biological therapeutics. The topological indices are numerical tendencies that often depict quantitative structural activity/property/toxicity relationships and correlate certain physico-chemical properties such as boiling point, stability, and strain energy, of respective nanomaterial. In this article, we established closed forms of various degree-based topological indices of semi-total line graph of 2D-lattice, nanotube and nanotorus of TUC4C8[r, s].
Topological indices play a very important role in the mathematical chemistry. The topological indices are numerical parameters of a graph. The degree sequence is obtained by considering the set of vertex degree of a graph. Graph operators are the ones which are used to obtain another broader graphs. This paper attempts to find degree sequence of vertex–F join operation of graphs for some standard graphs.