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Gemeri D, Tremblay J, Pastore M, Bahmann H. Electronic structure, optical properties, and electron dynamics in organic dye-sensitized TiO2 interfaces by local hybrid density functionals. Chem Phys 2022. [DOI: 10.1016/j.chemphys.2022.111521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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2
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Ensemble Density Functional Theory of Neutral and Charged Excitations : Exact Formulations, Standard Approximations, and Open Questions. Top Curr Chem (Cham) 2021; 380:4. [PMID: 34825294 DOI: 10.1007/s41061-021-00359-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 11/02/2021] [Indexed: 10/19/2022]
Abstract
Recent progress in the field of (time-independent) ensemble density-functional theory (DFT) for excited states are reviewed. Both Gross-Oliveira-Kohn (GOK) and N-centered ensemble formalisms, which are mathematically very similar and allow for an in-principle-exact description of neutral and charged electronic excitations, respectively, are discussed. Key exact results, for example, the equivalence between the infamous derivative discontinuity problem and the description of weight dependencies in the ensemble exchange-correlation density functional, are highlighted. The variational evaluation of orbital-dependent ensemble Hartree-exchange (Hx) energies is discussed in detail. We show in passing that state-averaging individual exact Hx energies can lead to severe (although solvable) v-representability issues. Finally, we explore the possibility of using the concept of density-driven correlation, which has been introduced recently and does not exist in regular ground-state DFT, for improving state-of-the-art correlation density-functional approximations for ensembles. The present review reflects the efforts of a growing community to turn ensemble DFT into a rigorous and reliable low-cost computational method for excited states. We hope that, in the near future, this contribution will stimulate new formal and practical developments in the field.
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Burton HGA, Marut C, Daas TJ, Gori-Giorgi P, Loos PF. Variations of the Hartree-Fock fractional-spin error for one electron. J Chem Phys 2021; 155:054107. [PMID: 34364354 DOI: 10.1063/5.0056968] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Fractional-spin errors are inherent in all current approximate density functionals, including Hartree-Fock theory, and their origin has been related to strong static correlation effects. The conventional way to encode fractional-spin calculations is to construct an ensemble density that scales between the high-spin and low-spin densities. In this article, we explore the variation of the Hartree-Fock fractional-spin (or ghost-interaction) error in one-electron systems using restricted and unrestricted ensemble densities and the exact generalized Hartree-Fock representation. By considering the hydrogen atom and H+ 2 cation, we analyze how the unrestricted and generalized Hartree-Fock schemes minimize this error by localizing the electrons or rotating the spin coordinates. We also reveal a clear similarity between the Coulomb hole of He-like ions and the density depletion near the nucleus induced by the fractional-spin error in the unpolarized hydrogen atom. Finally, we analyze the effect of the fractional-spin error on the Møller-Plesset adiabatic connection, excited states, and functional- and density-driven errors.
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Affiliation(s)
- Hugh G A Burton
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Clotilde Marut
- Laboratoire de Chimie et Physique Quantiques, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Timothy J Daas
- Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Faculty of Science, Vrije Universiteit, De Boelelaan 1083, 1081HV Amsterdam, The Netherlands
| | - Paola Gori-Giorgi
- Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Faculty of Science, Vrije Universiteit, De Boelelaan 1083, 1081HV Amsterdam, The Netherlands
| | - Pierre-François Loos
- Laboratoire de Chimie et Physique Quantiques, Université de Toulouse, CNRS, UPS, Toulouse, France
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4
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Kraisler E, Hodgson MJP, Gross EKU. From Kohn-Sham to Many-Electron Energies via Step Structures in the Exchange-Correlation Potential. J Chem Theory Comput 2021; 17:1390-1407. [PMID: 33595312 PMCID: PMC8363072 DOI: 10.1021/acs.jctc.0c01093] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
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Accurately
describing excited states within Kohn–Sham (KS)
density functional theory (DFT), particularly those which induce ionization
and charge transfer, remains a great challenge. Common exchange-correlation
(xc) approximations are unreliable for excited states owing, in part,
to the absence of a derivative discontinuity in the xc energy (Δ),
which relates a many-electron energy difference to the corresponding
KS energy difference. We demonstrate, analytically and numerically,
how the relationship between KS and many-electron energies leads to
the step structures observed in the exact xc potential in four scenarios:
electron addition, molecular dissociation, excitation of a finite
system, and charge transfer. We further show that steps in the potential
can be obtained also with common xc approximations, as simple as the
LDA, when addressed from the ensemble perspective. The article therefore
highlights how capturing the relationship between KS and many-electron
energies with advanced xc approximations is crucial for accurately
calculating excitations, as well as the ground-state density and energy
of systems which consist of distinct subsystems.
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Affiliation(s)
- Eli Kraisler
- Fritz Haber Center for Molecular Dynamics and Institute of Chemistry, The Hebrew University of Jerusalem, 9091401 Jerusalem, Israel
| | - M J P Hodgson
- Department of Physics, Durham University, South Road, Durham DH1 3LE, United Kingdom.,Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle, Germany
| | - E K U Gross
- Fritz Haber Center for Molecular Dynamics and Institute of Chemistry, The Hebrew University of Jerusalem, 9091401 Jerusalem, Israel
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Fabrizio A, Meyer B, Corminboeuf C. Machine learning models of the energy curvature vs particle number for optimal tuning of long-range corrected functionals. J Chem Phys 2020; 152:154103. [DOI: 10.1063/5.0005039] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Affiliation(s)
- Alberto Fabrizio
- Laboratory for Computational Molecular Design, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
- National Centre for Computational Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Benjamin Meyer
- Laboratory for Computational Molecular Design, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
- National Centre for Computational Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Clemence Corminboeuf
- Laboratory for Computational Molecular Design, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
- National Centre for Computational Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
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6
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Kraisler E. Asymptotic Behavior of the Exchange‐Correlation Energy Density and the Kohn‐Sham Potential in Density Functional Theory: Exact Results and Strategy for Approximations. Isr J Chem 2020. [DOI: 10.1002/ijch.201900103] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Eli Kraisler
- Fritz Haber Center for Molecular Dynamics and Institute of Chemistry The Hebrew University of Jerusalem 9091401 Jerusalem Israel
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7
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Gould T, Pittalis S, Toulouse J, Kraisler E, Kronik L. Asymptotic behavior of the Hartree-exchange and correlation potentials in ensemble density functional theory. Phys Chem Chem Phys 2019; 21:19805-19815. [DOI: 10.1039/c9cp03633d] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We show that the Hartree-exchange and correlation potentials of ensemble systems can have unexpected features, including non-vanishing asymptotic constants and non-trivial screening of electrons. These features are demonstrated here on Li, C, and F.
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Affiliation(s)
- Tim Gould
- Qld Micro- and Nanotechnology Centre
- Griffith University
- Nathan
- Australia
| | | | - Julien Toulouse
- Laboratoire de Chimie Théorique
- Sorbonne Université and CNRS
- F-75005 Paris
- France
| | - Eli Kraisler
- Fritz Haber Center for Molecular Dynamics and Institute of Chemistry
- The Hebrew University of Jerusalem
- 9091401 Jerusalem
- Israel
| | - Leeor Kronik
- Department of Materials and Interfaces
- Weizmann Institute of Science
- Rehovoth 76100
- Israel
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Hodgson MJP, Kraisler E, Schild A, Gross EKU. How Interatomic Steps in the Exact Kohn-Sham Potential Relate to Derivative Discontinuities of the Energy. J Phys Chem Lett 2017; 8:5974-5980. [PMID: 29179553 DOI: 10.1021/acs.jpclett.7b02615] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Accurate density functional calculations hinge on reliable approximations to the unknown exchange-correlation (xc) potential. The most popular approximations usually lack features of the exact xc potential that are important for an accurate prediction of the fundamental gap and the distribution of charge in complex systems. Two principal features in this regard are the spatially uniform shift in the potential, as the number of electrons infinitesimally surpasses an integer, and the spatial steps that form, for example, between the atoms of stretched molecules. Although both aforementioned concepts are well known, the exact relationship between them remained unclear. Here we establish this relationship via an analytical derivation. We support our result by numerically solving the many-electron Schrödinger equation to extract the exact Kohn-Sham potential and directly observe its features. Spatial steps in the exact xc potential of a full configuration-interaction (FCI) calculation of a molecule are presented in three dimensions.
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Affiliation(s)
- M J P Hodgson
- Max-Planck-Institut für Mikrostrukturphysik , Weinberg 2, D-06120 Halle, Germany
| | - Eli Kraisler
- Max-Planck-Institut für Mikrostrukturphysik , Weinberg 2, D-06120 Halle, Germany
| | - Axel Schild
- Laboratorium für Physikalische Chemie, ETH Zürich , 8093 Zürich, Switzerland
| | - E K U Gross
- Max-Planck-Institut für Mikrostrukturphysik , Weinberg 2, D-06120 Halle, Germany
- Fritz Haber Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem , Jerusalem 91904, Israel
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Wasserman A, Nafziger J, Jiang K, Kim MC, Sim E, Burke K. The Importance of Being Inconsistent. Annu Rev Phys Chem 2017; 68:555-581. [PMID: 28463652 DOI: 10.1146/annurev-physchem-052516-044957] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Adam Wasserman
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907
| | - Jonathan Nafziger
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
| | - Kaili Jiang
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907
| | - Min-Cheol Kim
- Department of Chemistry, Yonsei University, Seoul 03722, South Korea
| | - Eunji Sim
- Department of Chemistry, Yonsei University, Seoul 03722, South Korea
| | - Kieron Burke
- Department of Chemistry, University of California, Irvine, California 92697
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