Justification of relativistic Dirac-Hartree-Fock and configuration interaction

Before knowing that the relativistic Hamiltonian H does allow the existence of bounded states (H is unbounded from below and from above), the existence of SCF and beyond SCF solutions had to be assumed as an act of faith vindicated by consistent numerical results. A recent theorem showing the existence of such bounded states furnishes a rigorous framework for the relativistic theory of electronic bounded states.