https://doi.org/10.1351/goldbook.K03411
Directly relates experimental is given by the negative value of the energy of the orbital, , as calculated within the
ionization
potentials with energy levels of molecular orbitals. The theorem states that the ionization potential
required to remove an electron from the orbital Hartree
–Fock approximation. The theorem is not applied to localized molecular orbitals, which are not eigenfunctions of the effective hamiltonian.