Doubly Tuned Exchange–Correlation Functionals for Mixed-Reference Spin-Flip Time-Dependent Density Functional Theory

Journal of Chemical Theory and Computation, Journal Year: 2023, Volume and Issue: 19(21), P. 7671 - 7684

Published: Oct. 16, 2023

It is demonstrated that significant accuracy improvements in MRSF-TDDFT can be achieved by introducing two different exchange–correlation (XC) functionals for the reference Kohn–Sham DFT and response part of calculations, respectively. Accordingly, new XC doubly tuned Coulomb attenuated method-vertical excitation energy (DTCAM-VEE) DTCAM-AEE were developed on basis "adaptive exact exchange (AEE)" concept framework Coulomb-attenuating functionals. The values DTCAM-VEE are excellent agreement with those Thiel's set [mean absolute errors (MAEs) interquartile range (IQR) 0.218 0.327 eV, respectively]. On other hand, faithfully reproduced qualitative aspects conical intersections (CIs) trans-butadiene thymine nonadiabatic molecular dynamics (NAMD) simulations thymine. latter functional also remarkably exhibited 1/R asymptotic behavior charge-transfer state an ethylene–tetrafluoroethylene dimer accurate potential surfaces (PESs) along torsional angles retinal protonated Schiff base model six double bonds (rPSB6). Overall, generally performs well, as its MAE (0.237) IQR (0.41 eV) much improved compared to BH&HLYP. current idea applied well variants linear theories, opening a way developing

Language: Английский

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Aufbau Suppressed Coupled Cluster Theory for Electronically Excited States

Journal of Chemical Theory and Computation, Journal Year: 2024, Volume and Issue: 20(7), P. 2761 - 2773

Published: March 19, 2024

We introduce an approach to improve single-reference coupled cluster theory in settings where the Aufbau determinant is absent from or plays only a small role true wave function. Using de-excitation operator that can be efficiently hidden within similarity transform, we create function which de-excitations work suppress and produce functions dominated by other determinants. Thanks invertible fully exponential form, systematically improvable, size consistent, extensive, and, interestingly, intensive granular way should make adoption of some ground state techniques, such as local correlation, relatively straightforward. In this initial study, apply general formalism state-specific method for orbital-relaxed, singly excited states. find matches accuracy similar-cost equation-of-motion methods valence excitations while offering improved charge transfer also more accurate than excited-state-specific perturbation both types

Language: Английский

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A Critical Evaluation of the Hybrid KS DFT Functionals Based on the KS Exchange-Correlation Potentials

The Journal of Physical Chemistry Letters, Journal Year: 2024, Volume and Issue: unknown, P. 10219 - 10229

Published: Oct. 2, 2024

We have developed a critical methodology for the evaluation of quality hybrid exchange-correlation (XC) density functional approximations (DFAs) based on very fundamental quantities, i.e., Kohn-Sham (KS) XC potentials, self-consistent electron densities, first ionization potentials (IPs), and total energies. Since primary objects in current study, are not directly accessible hybrids, we calculate them by inverting KS densities. Utilizing this methodology, tested 155 DFAs available LIBXC library using FCI CCSD(T) methods as reference. found that group functionals produces decent mainly those with large mixture Hartree-Fock exchange. Moreover, value IP strongly depends potential quality. On other hand, show energy is dominated functional-driven error, which some cases leads to substantial errors electronic The study shows new directions constructing more accurate within KS-DFT framework.

Language: Английский

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Benchmarking time-dependent density functional theory for singlet excited states of thermally activated delayed fluorescence chromophores

Physical Review Research, Journal Year: 2022, Volume and Issue: 4(3)

Published: Aug. 24, 2022

Thermally activated delayed fluorescence (TADF) is the internal conversion of triplet excitons into singlet via reverse intersystem crossing. TADF can significantly enhance efficiency organic light-emitting diodes (OLEDs). In order for a chromophore to display energy difference between its lowest and states, ${S}_{1}$ ${T}_{1}$, should be as small possible. This requirement facilitated by spatial separation frontier orbitals. Computer simulations based on time-dependent density functional theory (TDDFT) have been used extensively predict excited state properties chromophores. However, accuracy TDDFT largely depends choice exchange-correlation functional. Here, we present benchmark study performance different classes hybrid functionals 16 chromophores consisting donor acceptor moieties. We find that only range-separated double functionals, $\ensuremath{\omega}\mathrm{B}2\mathrm{PLYP}$ $\ensuremath{\omega}\mathrm{B}2\mathrm{GP}\text{\ensuremath{-}}\mathrm{PLYP}$, provide qualitatively correct predictions relative excitation energies molecules, spectral composition ordering intramolecular charge-transfer versus valence states. Therefore, recommend using these assess prospective Nevertheless, further development needed improve quantitative TDDFT. These findings are important our ability computationally screen design candidate advance highly efficient OLEDs.

Language: Английский

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Earth Mover’s Distance as a Metric to Evaluate the Extent of Charge Transfer in Excitations Using Discretized Real-Space Densities

Journal of Chemical Theory and Computation, Journal Year: 2023, Volume and Issue: 19(21), P. 7704 - 7714

Published: Nov. 3, 2023

This paper presents a novel theoretical measure, μEMD, based on the earth mover's distance (EMD), for quantifying density shift caused by electronic excitations in molecules. As input, EMD metric uses only discretized ground- and excited-state electron densities real space, rendering it compatible with almost all structure methods used to calculate excited states. The is compared against other popular metrics describing extent of electron-hole separation wide range states (valence, Rydberg, charge transfer, etc.). results showcase metric's effectiveness across excitation types suggest that useful as an additional tool characterize excitations. study also reveals μEMD can function promising diagnostic predicting failure pure exchange-correlation functionals. Specifically, we show statistical relationships among functional-driven errors, exact exchange content within functional, magnitude values.

Language: Английский

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