Shifts of the levels of two identical molecules due to overlapping of their molecular orbitals

Two identical molecules with overlapping molecular orbitals are considered in the Hartree-Fock approximation as a single system, that is, the intermolecular orbital of the system is regarded as a linear combination of molecular orbitals belonging to one randomly degenerate level of both molecules. Analysis of the subsystem of equations obtained for these orbitals reveals that the splitting interval of a randomly degenerate level in the majority of cases is determined by molecular orbital overlapping, and the shift of the center of the family of levels is determined by the electrostatic interaction.