The use of the Dirac Hamiltonian as a relativistic substitute for the one electron terms of the traditional, non-relativistic many-electron Hamiltonian yields the Dirac-Coulomb Hamiltonian: one of the most widely used special-relativistic, many-electron Hamiltonians. This Hamiltonian may be utilized in conjunction with a Hartree-Fock-like wave-function in what is known as the Dirac-Hartree-Fock (DHF) method. The DHF method has a special status in quantum chemistry as it often is utilized to benchmark relativistic effects in the absence of electron correlation. Such benchmarks can provide a gauge of the accuracy of more approximate methods which attempt to include relativistic effects as a perturbation of the non-relativistic Hartree-Fock case as well as methods which employ transformed, simplified versions of the Dirac-Coulomb Hamiltonian.[4]