Double, Rydberg and charge transfer excitations from pairing matrix fluctuation and particle-particle random phase approximation

Yang, Yang; Aggelen, Helen van; Yang, Weitao

doi:10.1063/1.4834875

Cited by 59 publications

(120 citation statements)

References 52 publications

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“…This approximation leads to the working equation of pp-RPA using common DFAs as practiced in Ref. 11,13,16 . Additionally, TDDFT-P allows other pairing matrix dependent functionals E XC [ρ, κ] to be used to calculate N ± 2 excitations in the pp-RPA equation.…”

Section: Adiabatic Linear-response Tddft-p For Non-superconductimentioning

confidence: 99%

“…TDDFT-P can be a useful theory to capture N ± 2 excitations and correlation energies 16 , going beyond the simplest pp-RPA.…”

Section: Linear-response Tddft-p With Frequency-dependent Pp Kernelsmentioning

confidence: 99%

“…pp-RPA 9,10 , has been used to calculate the Auger spectroscopy 36 39 . Recently, Yang et al 16 developed a scheme to calculate neutral excitations based on pp-RPA, demonstrating promising results. To capture the e ect beyond the mean-eld approximation, one can resort to ab initio wavefunction techniques, which utilize correlated ground state wavefunctions and include higher order excitation operators.…”

Section: Introductionmentioning

confidence: 99%

“…Both the adiabatic and non-adibatic versions of linear-response TDDFT-P are explored. Especially, the adiabatic TDDFT-P justi ed the practice of utilizing orbitals and eigenvalues of common DFAs in pp-RPA equations 11,13,16 . Such an extension enables us to capture e ects beyond mean-eld approximations in N ± 2 excitations, and would also make it possible to capture neutral excitations better by suitable approaches 16,42 .…”

Section: Introductionmentioning

confidence: 99%

“…Theoretical analysis reveals that the correlation energy from pp-RPA with Hartree-Fock references is equivalent to ladder-coupled-cluster doubles 14,15 . Additionally, the N ± 2 excitation energies from pp-RPA can be used to capture valence, double, charge transfer, and Rydberg excitations with a potential O(N 4 ) scaling 16 . Viewed as an approximation to the pairing-matrix-pairing matrix (pp) response function, in this paper we establish the connection of the pp-RPA formalism to the timedependent density-functional theory (TDDFT) for superconductors 17,18 as a special case for non-superconducting system.…”

Section: Introductionmentioning

confidence: 99%

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Linear-response time-dependent density-functional theory with pairing fields

Peng

Aggelen

Yang

et al. 2014

The Journal of Chemical Physics

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Recent development in particle-particle random phase approximation (pp-RPA) broadens the perspective on ground state correlation energies (van Aggelen et al. Phys. Rev. A, 88, 030501 (2013)) and N ± 2 excitation energies (Yang, et al. J.Chem. Phys.). So far Hartree-Fock and approximated density-functional orbitals have been utilized to evaluate the pp-RPA equation. In this paper, to further explore the fundamentals and the potential use of pairing matrix dependent functionals, we present the linear-response time-dependent density-functional theory with pairing elds with both adiabatic and frequency-dependent kernels. This theory is related to the density-functional theory and time-dependent density-functional theory for superconductors, but is applied to normal non-superconducting systems for our purpose. Due to the lack of the proof of the one-to-one mapping between the pairing matrix and the pairing eld for time-dependent systems, the linear-response theory is established based on the representability assumption of the pairing matrix. The linear response theory justi es the use of approximated density-functionals in the pp-RPA equation. This work sets the fundamentals for future density-functional development to enhance the description of ground state correlation energies and N ± 2 excitation energies.

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Section: Adiabatic Linear-response Tddft-p For Non-superconductimentioning

confidence: 99%

“…TDDFT-P can be a useful theory to capture N ± 2 excitations and correlation energies 16 , going beyond the simplest pp-RPA.…”

Section: Linear-response Tddft-p With Frequency-dependent Pp Kernelsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Linear-response time-dependent density-functional theory with pairing fields

Peng

Aggelen

Yang

et al. 2014

The Journal of Chemical Physics

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Fast and Accurate Determination of the Singlet–Triplet Gap in Donor–Acceptor and Multiresonance TADF Molecules by Using Hole–Hole Tamm–Dancoff Approximated Density Functional Theory

Woon

Nikishau

Sini

2022

Advcd Theory and Sims

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One of the requirements to design efficient emitters based on the multiresonance (MR)‐ or donor–acceptor (D‐A) thermally activated delayed fluorescence (TADF) materials is a relatively small energy gap between the lowest singlet and triplet excited states (ΔEST). High‐level ab initio calculations of their ΔEST provide benchmark results, but they are very time consuming and little practical for large‐size systems. Here, the performances of hole–hole Tamm–Dancoff approximated density functional theory (hh‐TDA‐DFT) and the functional dependent accuracy of hh‐TDA are examined on ΔEST of a large number of MR‐ and D‐A TADF molecules. The results indicate that hh‐TDA combined with the hybrid functional B3LYP can predict ΔEST values for a wide number of MR‐TADF molecules with mean absolute error (MAE) within 0.04 eV with correlation as high as 0.75. For D‐A TADF molecules, ΔEST is less sensitive to the nature of the functionals, with MAE as low as 0.07 eV. The larger discrepancy between ΔEST obtained from hh‐TDA‐DFT and experimental data in several oxygen‐containing MR‐TADF molecules is assumed to stem from the aggregation tendency of these compounds in solution. These findings provide important insights on the role of aggregation in reducing the ΔEST of MR‐TADF compounds.

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Conceptual Insights into DFT Spin‐State Energetics of Octahedral Transition‐Metal Complexes through a Density Difference Analysis

Pintér

Chankisjijev

Geerlings

et al. 2017

Chemistry A European J

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In this study, an intuitive concept is derived, which explains the characteristic dependence of spin-state energetics on the exact exchange admixture of DFT functionals in the case of octahedral transition metal complexes. The change in electron density distributions upon varying the admixture, c , in the B3LYP functional is analyzed for archetype ionic and covalent systems as well as for the Fe ion in an ideal octahedral field. An understanding of how the DFT description of the electronic structure of octahedral complexes changes as a function of c is sought. A systematic spin-state energy analysis of 50 octahedral complexes of various metals and ligands with consistent experimental data is presented, allowing the derivation, in theory, of an optimal c value for each system. The notion that the admixture dependence of DFT spin-state energetics stems from the treatment of nondynamic electrons arising from the mixing of (M-Lz2 ) (dz2 ) and (M-Lx2-y2 ) (dx2-y2 ) configurations into the dominant (M-Lx2-y2 ) (dx2-y2 ) and (M-Lx2-y2 ) (dx2-y2 ) ones in the low(er) spin states is put forward. That is, in the effort to mimic such electron-electron interactions, E overestimates, whereas exact exchange downplays the contribution of this type of electron correlation to the stability of low(er) spin states, leading to the widespread practical observation that the higher the exact exchange admixture, the more stable the high-spin-state configuration.

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Double, Rydberg and charge transfer excitations from pairing matrix fluctuation and particle-particle random phase approximation

Cited by 59 publications

References 52 publications

Linear-response time-dependent density-functional theory with pairing fields

Linear-response time-dependent density-functional theory with pairing fields

Fast and Accurate Determination of the Singlet–Triplet Gap in Donor–Acceptor and Multiresonance TADF Molecules by Using Hole–Hole Tamm–Dancoff Approximated Density Functional Theory

Conceptual Insights into DFT Spin‐State Energetics of Octahedral Transition‐Metal Complexes through a Density Difference Analysis

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