Effective Potential for Natural Spin Orbitals

Abstract

For the first time the explicit form of the effective nonlocal potential for the natural spin orbitals is derived and analyzed. It is shown that in the case of the degenerate one-electron reduced density matrix the potential is not unique. The knowledge of the effective potential allows one to establish one-electron equations for the natural spin orbitals that may be of great value for efficient density matrix functional theory calculations.