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Title: System-dependent exchange–correlation functional with exact asymptotic potential and ε{sub HOMO} ≈ − I

Abstract

Density scaling considerations are used to derive an exchange–correlation explicit density functional that is appropriate for the electron deficient side of the integer and which recovers the exact r → ∞ asymptotic behaviour of the exchange–correlation potential. The functional has an unconventional mathematical form with parameters that are system-dependent; the parameters for an N-electron system are determined in advance from generalised gradient approximation (GGA) calculations on the N- and (N − 1)-electron systems. Compared to GGA results, the functional yields similar exchange–correlation energies, but HOMO energies that are an order of magnitude closer to the negative of the vertical ionisation potential; for anions, the HOMO energies are negative, as required. Rydberg excitation energies are also notably improved and the exchange–correlation potential is visibly lowered towards the near-exact potential. Further development is required to improve valence excitations, static isotropic polarisabilities, and the shape of the potential in non-asymptotic regions. The functional is fundamentally different to conventional approximations.

Authors:
Publication Date:
OSTI Identifier:
22489721
Resource Type:
Journal Article
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 143; Journal Issue: 2; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-9606
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 97 MATHEMATICAL METHODS AND COMPUTING; ANIONS; COMPARATIVE EVALUATIONS; DENSITY; DENSITY FUNCTIONAL METHOD; ELECTRONS; EXCITATION; POLARIZABILITY

Citation Formats

Gledhill, Jonathan D., and Tozer, David J., E-mail: d.j.tozer@durham.ac.uk. System-dependent exchange–correlation functional with exact asymptotic potential and ε{sub HOMO} ≈ − I. United States: N. p., 2015. Web. doi:10.1063/1.4926397.
Gledhill, Jonathan D., & Tozer, David J., E-mail: d.j.tozer@durham.ac.uk. System-dependent exchange–correlation functional with exact asymptotic potential and ε{sub HOMO} ≈ − I. United States. https://doi.org/10.1063/1.4926397
Gledhill, Jonathan D., and Tozer, David J., E-mail: d.j.tozer@durham.ac.uk. 2015. "System-dependent exchange–correlation functional with exact asymptotic potential and ε{sub HOMO} ≈ − I". United States. https://doi.org/10.1063/1.4926397.
@article{osti_22489721,
title = {System-dependent exchange–correlation functional with exact asymptotic potential and ε{sub HOMO} ≈ − I},
author = {Gledhill, Jonathan D. and Tozer, David J., E-mail: d.j.tozer@durham.ac.uk},
abstractNote = {Density scaling considerations are used to derive an exchange–correlation explicit density functional that is appropriate for the electron deficient side of the integer and which recovers the exact r → ∞ asymptotic behaviour of the exchange–correlation potential. The functional has an unconventional mathematical form with parameters that are system-dependent; the parameters for an N-electron system are determined in advance from generalised gradient approximation (GGA) calculations on the N- and (N − 1)-electron systems. Compared to GGA results, the functional yields similar exchange–correlation energies, but HOMO energies that are an order of magnitude closer to the negative of the vertical ionisation potential; for anions, the HOMO energies are negative, as required. Rydberg excitation energies are also notably improved and the exchange–correlation potential is visibly lowered towards the near-exact potential. Further development is required to improve valence excitations, static isotropic polarisabilities, and the shape of the potential in non-asymptotic regions. The functional is fundamentally different to conventional approximations.},
doi = {10.1063/1.4926397},
url = {https://www.osti.gov/biblio/22489721}, journal = {Journal of Chemical Physics},
issn = {0021-9606},
number = 2,
volume = 143,
place = {United States},
year = {Tue Jul 14 00:00:00 EDT 2015},
month = {Tue Jul 14 00:00:00 EDT 2015}
}