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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

The Devil's Triangle of Kohn-Sham density functional theory and excited states

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Author(s):
Mendes, Rodrigo A. [1, 2] ; Haiduke, Roberto L. A. [1] ; Bartlett, Rodney J. [2]
Total Authors: 3
Affiliation:
[1] Univ Sao Paulo, Inst Quim Sao Carlos, Dept Quim & Fis Mol, CP 780, BR-13560970 Sao Carlos, SP - Brazil
[2] Univ Florida, Quantum Theory Project, Gainesville, FL 32611 - USA
Total Affiliations: 2
Document type: Journal article
Source: Journal of Chemical Physics; v. 154, n. 7 FEB 21 2021.
Web of Science Citations: 0
Abstract

Exchange-correlation (XC) functionals from Density Functional Theory (DFT) developed under the rigorous arguments of Correlated Orbital Theory (COT) address the Devil's Triangle of prominent errors in Kohn-Sham (KS) DFT. At the foundation of this triangle lie the incorrect one-particle spectrum, the lack of integer discontinuity, and the self-interaction error. At the top level, these failures manifest themselves in incorrect charge transfer and Rydberg excitation energies, along with poor activation barriers. Accordingly, the Quantum Theory Project (QTP) XC functionals have been created to address several of the long-term issues encountered in KS theory and its Time Dependent DFT (TDDFT) variant for electronic excitations. Recognizing that COT starts with a correct one-particle spectrum, a condition imposed on the QTP functionals by means of minimum parameterization, the question that arises is how does this affect the electronically excited states? Among up to 28 XC functionals considered, the QTP family provides one of the smallest mean absolute deviations for charge-transfer excitations while also showing excellent results for Rydberg states. However, there is some room for improvement in the case of excitation energies to valence states, which are systematically underestimated by all functionals investigated. An alternative path for better treatment of excitation energies, mainly for valence states, is offered by using orbital energies from QTP functionals, especially by CAM-QTP-02 and LC-QTP. In this case, the deviations from the reference data can be reduced approximately by half. (AU)

FAPESP's process: 14/23714-1 - Electronic structure relativistic calculations for evaluation of new prolapse-free basis sets
Grantee:Roberto Luiz Andrade Haiduke
Support Opportunities: Regular Research Grants