Abstract
If is a determinantal eigenfunction for the -fermion Hamiltonian, , with one- and two-body terms, then , where is the ground-state energy, is the one-body reduced density matrix of , and is the well-known expression in terms of direct and exchange energies. If an arbitrary one-body is given, which does not come from a determinantal , then does not necessarily hold. This Letter proves, however, that if the two-body part of is positive, then in fact , where is the Hartree-Fock ground-state energy.
- Received 10 December 1980
DOI:https://doi.org/10.1103/PhysRevLett.46.457
©1981 American Physical Society