Work

Excitations and benchmark ensemble density functional theory for two electrons

Year: 2014

Type: article

Abstract: A new method for extracting ensemble Kohn-Sham potentials from accurate excited state densities is applied to a variety of two-electron systems, exploring the behavior of exact ensemble density functional theory. The issue of separating the Hartree energy and the choice of degenerate eigenstates is explored. A new approximation, spin eigenstate Hartree-exchange, is derived. Exact conditions that are proven include the signs of the correlation energy components and the asymptotic behavior of the potential for small weights of the excited states. Many energy components are given as a function of the weights for two electrons in a one-dimensional flat box, in a box with a large barrier to create charge transfer excitations, in a three-dimensional harmonic well (Hooke's atom), and for the He atom singlet-triplet ensemble, singlet-triplet-singlet ensemble, and triplet bi-ensemble.

Source: The Journal of Chemical Physics

DOI: 10.1063/1.4872255

Authors: Aurora Pribram-Jones, Zeng-hui Yang, John R. Trail, Kieron Burke, Richard J. Needs, Carsten A. Ullrich

Institutions: University of California, Irvine, University of Missouri, University of Cambridge

Language: English

Topic: Advanced Chemical Physics Studies

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: National Science Foundation, Engineering and Physical Sciences Research Council