Following our focus on the unrestricted-calculation, let's suppose we complete a unrestricted-SCF calculation, see the appendix, then we obtain the MO-coefficients {C ↑ , C ↓ } which not only yield orthogonal states, but are minimized to a mean-field shielding of the electronic charges. This forms a foundation to build beyond the mean-field approximation, and these theories, including CI are called post-HF or post-SCF. Using these coefficients the 1-body and 2-body interactions may be formed by dressing the atomic-centric interactions given by the Atomic Orbital, i.e. AO-arrays. This dressed interaction is called the Spin-Orbit (SO) representation, and serves as the playground where CI games occur. That is to say, CI theory itself keeps the same level of SCF shielding throughout all electronic states 7 .