Chemistry wiener index of lexicographic product digraphs

The wiener index was first proposed by organic chemist Wiener. It is a molecular model with exact physical and chemical properties in hydrocarbons using graph theory. It is an effective tool for quantitatively studying the structural relationships of organic compounds. So using the graph theory and electron microscopy to study the topological structure of molecules has been adopted by a large number of chemists. Research activities in this field have always been a hot issue in the chemical community. In this paper, according to the method of lexicographic product, a large graph is constructed from some known small graphs, and the wiener index of the large graph is given by using the extremum method. Similarly, according to the lexicographic product method, we can construct large molecular graphs with some existing small molecular graphs purposefully. According to the obtained wiener index, the physical and chemical properties of the corresponding molecules can be estimated, and then the microstructures of the molecules can be modified by electron microscopy, which plays an important guiding role in the purposeful synthesis of some molecules, materials and drugs.