Abstract: This experiment aims to train undergraduate students to use Excel to generate cross-sectional contour maps of π molecular orbitals through the Hückel molecular orbital (HMO) method. These maps can intuitively display the π electron distribution and properties of simple conjugate systems, such as butadiene and benzene. The contour maps generated from this experiment can be used to address specific chemical problems and summarize chemical principles, such as the relationship between the number of nodal surfaces and energy levels of π orbitals, and determining the stereoselectivity of electrocyclization reactions. By combining quantum chemical calculations with molecular structural property predictions, this experiment helps undergraduate students master the application of molecular orbital theory and is easy to promote.

Key words: HMO method, Molecular orbitals, Excel, Cross-sectional contour maps