Second Zagreb index of inorganic acid

In chemical graph theory, molecules are represented as mathematical graphs, where atoms are vertices and covalent bonds are edges. This abstraction allows the application of graph theoretical tools to study molecular structure and behavior. A variety of topological indices have been developed to quantify molecular features such as size, branching, and connectivity. The first Zagreb index M1 and the second Zagreb index M2, introduced by Gutman and Trinajstić [1], are among the most widely used descriptors [1]. But We propose these indices in inorganic acids Compound Formula Zagreb Index M2 Hydrochloric Acid HCl 1 Hydrobromic Acid HBr 1 Hydroiodic Acid HI 1 Hydrogen Fluoride HF 1 Hypobromous Acid HOBr 4 Reference: [1] Asaduzzaman M. The Tareq Index (TI): A novel graph-based descriptor for inorganic acids. J Graph Theory Combin Math. 2025;1(1). Available from: https://opentiers.org/index.php/jgtcm/article/view/5/5