Single determinant approximation for ground and excited states with accuracy comparable to that of the configuration interaction

S. Thanos, A. K. Theophilou, M. Tassi

It was realized from the early days of Chemical Physics (Rev. Mod. Phys. 35, 496 (1963)) that the energy $E_{HF}$ of the Slater determinant (SlDet) $|{\Phi }_{HF}⟩$, obtained by th…