where $h$ is \begin{equation} h(i) = \frac{{\bf p_i^2}}{2m} - \frac{e^{2}}{4\pi\epsilon_{0}} \frac{Z}{r} + u_{HF}(i). \end{equation}%% % 8 The last term, $u_{HF}(i)$ is called the Hartree-Fock potential.