Intramolecular charge-transfer excitation energies from range-separated hybrid functionals using the Yukawa potential

2009 ◽  
Vol 109 (9) ◽  
pp. 1905-1914 ◽  
Author(s):  
Yoshinobu Akinaga ◽  
Seiichiro Ten-No
Keyword(s):  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Yukawa Potential ◽  
Excitation Energies ◽  
Charge Transfer Excitation ◽  
Hybrid Functionals

scholarly journals Predicting Excitation Energies of Twisted Intramolecular Charge-Transfer States with Time-Dependent Density Functional Theory: Comparison with Experimental Measurements in the Gas-Phase and Solvents Ranging from Hexanes to Acetonitrile

2020 ◽  
Author(s):  
James Shee ◽  
Martin Head-Gordon
Keyword(s):  
Charge Transfer ◽  
Gas Phase ◽  
Excited States ◽  
Linear Response ◽  
Density Functional ◽  
Intramolecular Charge Transfer ◽  
Experimental Measurements ◽  
Excitation Energies ◽  
Donor And Acceptor ◽  
Donor Acceptor

Electronically-excited states characterized by intramolecular charge-transfer play an essential role in many biological processes and optical devices. The ability to make quantitative ab initio predictions of the relative energetics involved is a challenging yet desirable goal, especially for large molecules in solution. In this work we present a data set of 61 experimental measurements of absorption and emission processes, both in the gas phase and solvents representing a broad range of polarities, which involve intramolecular charge-transfer mediated by a non-zero, “twisted” dihedral angle between one or more donor and acceptor subunits. Among a variety of density functionals investigated within the framework of linear-response theory, the “optimally tuned” LRC-ωPBE functional, which utilizes a system-specific yet non-empirical procedure to specify the range-separation parameter, emerges as the preferred choice. For the entire set of excitation energies, involving changes in dipole moment ranging from 4 to >20 Debye, the mean signed and absolute errors are 0.02 and 0.18 eV, respectively (compared, e.g., to -0.30 and 0.30 for PBE0, 0.44 and 0.47 for LRC-ωPBEh, 0.83 and 0.83 for ωB97X-V). The performance of polarizable continuum solvation models for these charge-transfer excited states is closely examined, and clear trends emerge when measurements corresponding to the four small DMABN-like molecules and a charged species are excluded. We make the case that the large errors found only for small molecules in the gas phase and weak solvents cannot be expected to improve via the optimal tuning procedure, which enforces a condition that is exact only in the wellseparated donor-acceptor limit, and present empirical evidence implicating the outsized importance for small donor-acceptor systems of relaxation effects that cannot be accounted for by linear-response TDDFT within the adiabatic approximation. Finally, we demonstrate the utility of the optimally tuned density functional approach by targeting the charge-transfer states of a large biomimetic model system for light-harvesting structures in Photosystem II.

scholarly journals Predicting Excitation Energies of Twisted Intramolecular Charge-Transfer States with Time-Dependent Density Functional Theory: Comparison with Experimental Measurements in the Gas-Phase and Solvents Ranging from Hexanes to Acetonitrile

2020 ◽  
Author(s):  
James Shee ◽  
Martin Head-Gordon
Keyword(s):  
Charge Transfer ◽  
Gas Phase ◽  
Excited States ◽  
Linear Response ◽  
Density Functional ◽  
Intramolecular Charge Transfer ◽  
Experimental Measurements ◽  
Excitation Energies ◽  
Donor And Acceptor ◽  
Donor Acceptor

Electronically-excited states characterized by intramolecular charge-transfer play an essential role in many biological processes and optical devices. The ability to make quantitative ab initio predictions of the relative energetics involved is a challenging yet desirable goal, especially for large molecules in solution. In this work we present a data set of 61 experimental measurements of absorption and emission processes, both in the gas phase and solvents representing a broad range of polarities, which involve intramolecular charge-transfer mediated by a non-zero, “twisted” dihedral angle between one or more donor and acceptor subunits. Among a variety of density functionals investigated within the framework of linear-response theory, the “optimally tuned” LRC-ωPBE functional, which utilizes a system-specific yet non-empirical procedure to specify the range-separation parameter, emerges as the preferred choice. For the entire set of excitation energies, involving changes in dipole moment ranging from 4 to >20 Debye, the mean signed and absolute errors are 0.02 and 0.18 eV, respectively (compared, e.g., to -0.30 and 0.30 for PBE0, 0.44 and 0.47 for LRC-ωPBEh, 0.83 and 0.83 for ωB97X-V). The performance of polarizable continuum solvation models for these charge-transfer excited states is closely examined, and clear trends emerge when measurements corresponding to the four small DMABN-like molecules and a charged species are excluded. We make the case that the large errors found only for small molecules in the gas phase and weak solvents cannot be expected to improve via the optimal tuning procedure, which enforces a condition that is exact only in the wellseparated donor-acceptor limit, and present empirical evidence implicating the outsized importance for small donor-acceptor systems of relaxation effects that cannot be accounted for by linear-response TDDFT within the adiabatic approximation. Finally, we demonstrate the utility of the optimally tuned density functional approach by targeting the charge-transfer states of a large biomimetic model system for light-harvesting structures in Photosystem II.

Charge transfer excitation energies in pyridine–silver complexes studied by a QM/MM method

2009 ◽  
Vol 470 (4-6) ◽  
pp. 285-288 ◽  
Author(s):  
Vaida Arcisauskaite ◽  
Jacob Kongsted ◽  
Thorsten Hansen ◽  
Kurt V. Mikkelsen
Keyword(s):  
Charge Transfer ◽  
Silver Complexes ◽  
Excitation Energies ◽  
Charge Transfer Excitation

scholarly journals An accurate and linear-scaling method for calculating charge-transfer excitation energies and diabatic couplings

2013 ◽  
Vol 138 (5) ◽  
pp. 054101 ◽  
Author(s):  
Michele Pavanello ◽  
Troy Van Voorhis ◽  
Lucas Visscher ◽  
Johannes Neugebauer
Keyword(s):  
Charge Transfer ◽  
Linear Scaling ◽  
Excitation Energies ◽  
Scaling Method ◽  
Charge Transfer Excitation
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