The g-Hartree theory of orbital collapse

It is clear that, in the Ba+ problem, with an nf wavefunction poised on the knife edge between the two potential wells, there is an extremely sensitive dependence on the accuracy of the effective mean field. Hartree-Fock theory provides a first-order description of the phenomena involved, but 

It was pointed out in chapter 1 that there exist alternative mean-field theories to the Hartree-Fock method. In particular, one of these, the 7-Hartree method, is a fully relativistic theory which determines the optimum mean field in such a way as to make the Lagrangian of quantum field theory stationary. This is a fundamental choice, but turns out [230] to be satisfied by a whole family of SCF potentials of the general form 

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