Natural Spin-Orbitals and Generalized Overlap Amplitudes
Osvaldo Goscinski, Peter Lindner · Journal of Mathematical Physics · 1970
The generalized overlap amplitudes for ``hole'' states which appear in the one-particle Green's function are, in general, not linearly independent. We show that canonical orthonormalization of them yields the natural spin-orbitals (eigenfunctions of the first-order reduced density matrix).