Practical classes in quantum chemistry involve the calculation of the electronic characteristics of molecules by the simplest of semi-empirical methods in the Hckel approximation. The method allows simple examples to consider the structure of molecular orbitals and calculate the indices of the electronic structure to judge the chemical properties of molecules and their reactivity. Methodical instructions are intended for practical work on the discipline "Quantum chemistry" for students, specialties 011000, in the study of the disciplines "Quantum chemistry", "Construction of matter", special courses related to the study and application of computational methods of quantum chemistry