Hartree-Fock model, energy relationships

However, one must also be cautious when interpreting the results of approximate MO models. It is all too easy to endow the approximate method with the same virtues as the more rigorous ab initio scheme from which they are derived. Fenske has described [23] some of the possible pitfalls. For example, in Hartree-Fock theory there is a rigorous relationship between the stability of a molecule and its computed energy. Taking two isomeric species as an example, the one with the lowest computed energy is predicted to be the most stable. This relationship is often employed with approximate MO methods but it is no longer strictly valid. 

The model relies on the assumption that the HOMO energy of a complex is linearly related to its redox potential. This has been extensively investigated in the past and shown often to be true for homologous series of complexes. Thus, Sarapu and Fenske illustrated such a relationship between the HOMO energy calculated by the Hartree-Fock method, and the observed metal-centered oxidation potential in the series [Mn(CO)6 (CNMe) ]" ... 

While accurate, direct calculation of f-state energy structure is not generally feasible for lanthanide and actinide ions, parametric models for f-state energy-level structure determination have been developed that take advantage of relationships established by relativistie Hartree-Fock calculations (Crosswhite and Crosswhite 1984). Works by Cowan (1981) and Szasz (1992) should be consulted for additional information on theoretical atomic spectroscopy and relativistic Hartree-Fock calculations. 

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