Excited-state Koopmans theorem for ensembles

M. Levy, Nagy

Research output: Contribution to journalArticle

56 Citations (Scopus)


Koopmans’s theorem is generalized for excited-state ensemble density-functional theory. Formal expressions are derived that relate orbital energy differences to exchange-only excitation energies. These expressions provide stringent requirements for approximating the universal exchange component of the exact exchange-correlation functional for excited-state ensembles, and the expressions lead to a relation, containing a correlation potential, that gives exact excited-state ionization energies.

Original languageEnglish
Pages (from-to)1687-1689
Number of pages3
JournalPhysical Review A - Atomic, Molecular, and Optical Physics
Issue number2
Publication statusPublished - Jan 1 1999


ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

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