specifically the parameter regime in which U >> t. The ground-state, when half-filled, involves strongly localized electrons coupled antiferromagnetically; doping gives rise to more exotic orders. 3. Electrons are substantially "entangled." From an information theory perspective, this can refer to entanglement entropy, e.g. Shannon or Renyi formulations. Concepts such as 1-and 2orbital entanglement entropies have also been proposed. 4. The overlap of the Hartree-Fock (HF) state or the largest-weighted configuration in a multi-determinant expansion with the true ground-state is small.