Direct Extraction of Excitation Energies from Ensemble Density-Functional Theory

ORAL

Abstract

A very specific ensemble of ground and excited states is shown to yield an exact formula for any excitation energy as a simple correction to the energy difference between orbitals of the Kohn-Sham ground state. This alternative scheme avoids either the need to calculate many unoccupied levels as in time-dependent density functional theory (TDDFT) or the need for many self-consistent ensemble calculations. The symmetry-eigenstate Hartree-exchange (SEHX) approximation yields results comparable to standard TDDFT for atoms. With this formalism, SEHX yields approximate double excitations, which are missed by adiabatic TDDFT.

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Presenters

  • Zenghui Yang

    Microsystem and Terahertz Research Center, China Academy of Engineering Physics

Authors

  • Zenghui Yang

    Microsystem and Terahertz Research Center, China Academy of Engineering Physics

  • Aurora Pribram-Jones

    Lawrence Livermore National Lab, Department of Chemistry, University of California, Berkeley, Quantum Simulations Group/Department of Chemistry, LLNL/UC Berkeley

  • Kieron Burke

    Physics and Chemistry, Univ of California - Irvine, Chemistry, Univ of California - Irvine, University of California Irvine, Chemistry, University of California, Chemistry, University of California, Irvine, University of California, Irvine, Univ of California - Irvine, Department of Chemistry, University of California-Irvine

  • Carsten Ullrich

    Physics and Astronomy, University of Missouri, Univ of Missouri - Columbia, University of Missouri, Department of Physics and Astronomy, University of Missouri, Columbia