Topological indices are numerical parameters associated with underlying topology of a molecular structure. They are correlated with several physio-chemical properties of chemical compounds. Recently, Euclidean metric based topological index has been introduced named as Sombor index. Therefore, in this article, we will discuss combinatorial aspects and compute Sombor index, average Sombor index and the reduced Sombor index of line graph of silicate carbides Si₂C₃-I[p, q].

Cheminformatics is a modern field of chemistry information science and mathematics that is very much helpful in keeping the data and getting information about chemicals. A new two-dimensional carbon known as diphenylene was identified and synthesized. It is considered one of the materials that have many applications in most fields such as catalysis. The number of spanning trees of a graph G, also known as the complexity of a graph G, denoted by τ(G), is an important, well-studied quantity in graph theory, and appears in a number of applications. In this paper, we introduce a new chemical compound that is a chain of diphenylene where any two diphenylene intersect by one edge. We derive two formulas for the number of spanning trees in a chain of diphenylene planar graphs that have connected intersection of one edge but where the diphenylenes have same sizes.

W_p (G) is Wiener polarity index of the graph G that is defined as the numeral of unordered pairs of vertices which are at distance three in G. W_p (G) is considered as one of the classic topological indices and its properties have been widely studied for numerous graphs in recent years. In the currnt article an exact formula for the Wiener polarity index of nanostar dendrimers is computed.

Mathematical topological characterization of chemical graphs gives information about some physical properties of molecules. Classical degree based topological indices of copper oxide have been recently calculated. Ve-degree and Ev-degree based topological indices have been newly defined in graph theory. In this study we investigate ve-degree topological properties of copper oxide. We calculate ve-degree Zagreb and Randić indices of copper oxide.

Let G = (V, F) be a simple connected molecular graph with the vertex set V = V(G) and the edge set E = E(G). The second and third harmonic indices have been introduced as H-2 (G) = Sigma(uv is an element of E(G)) 2/n(u) + n(v) and H-3 (G) = Sigma(uv is an element of E(G)) 2/m(u) + m(v), where n(u) is the number of vertices of G lying closer to u and m(u) is the number of edges of G lying closer to n than to v. The goal of this paper is computing the harmonic indices of a class of benzenoid numelis: "Circumcoronene series of benzenoid H-k" and "Polycyclic Aromatic Hydrocarbons PAH(k)" for all positive integer number k.

A topological index is a real number which is same under graph isomorphism and it is derived from a graph by mathematically. In chemical graph theory, a molecular graph is a simple graph having no loops and multiple edges in which atoms and chemical bonds are represented by vertices and edges respectively. Topological indices defined on these chemical molecular structures can help researchers better understand the physical features, chemical reactivity, and biological activity. In this paper, we compute general expressions of some degree based topological indices of a special graph named as mk-graph for some positive integer k.