title: Natural occupation numbers in two-electron quantum rings.
abstract: Natural orbitals (NOs) are central constituents for evaluating correlation energies through efficient approximations. Here, we report the closed-form expression of the NOs of two-electron quantum rings, which are prototypical finite-extension systems and new starting points for the development of exchange-correlation functionals in density functional theory. We also show that the natural occupation numbers for these two-electron paradigms are in general non-vanishing and follow the same power law decay as atomic and molecular two-electron systems.
authors: Normandy Univ., COBRA UMR 6014 & FR 3038, Université de Rouen, INSA Rouen, CNRS, 1 rue Tesniére, 76821 Mont Saint Aignan, Cedex, France.
authors: Vincent
authors: V
authors: Tognetti
authors: Research School of Chemistry, Australian National University, Canberra ACT 2601, Australia.
authors: Pierre-François
authors: PF
authors: Loos