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arXiv · 2307.00187

Exact Conditions for Ensemble Density Functional Theory

Thais R. Scott·John Kozlowski·Steven Crisostomo·Aurora Pribram-Jones·Kieron Burke
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Abstract

Ensemble density functional theory (EDFT) is a promising alternative to time-dependent density functional theory for computing electronic excitation energies. Using coordinate scaling, we prove several fundamental exact conditions in EDFT and illustrate them on the exact singlet bi-ensemble of the Hubbard dimer. Several approximations violate these conditions, and some ground-state conditions from quantum chemistry do not generalize to EDFT. The strong-correlation limit is derived for the dimer, revealing weight-dependent derivative discontinuities in EDFT.

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Thais R. Scott, John Kozlowski, Steven Crisostomo, Aurora Pribram-Jones, Kieron Burke. 2023-07-01. Exact Conditions for Ensemble Density Functional Theory. https://arxiv.org/abs/2307.00187

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