Exciton sizes of conducting polymers predicted by time-dependent density functional theory

Tretiak, Sergei; Igumenshchev, Kirill; Chernyak, Vladimir

doi:10.1103/physrevb.71.033201

Cited by 205 publications

(200 citation statements)

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“…This positive correlation can be understood as the onset of exciton binding. This result sheds new light on the observations by Tretiak et al 39 that bound excitons in large conjugated systems can only be described by LRC functionals.…”

mentioning

confidence: 74%

Communication: Exciton analysis in time-dependent density functional theory: How functionals shape excited-state characters

Mewes

Plasser

Dreuw

2015

The Journal of Chemical Physics

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Excited-state descriptors based on the one-particle transition density matrix referring to the exciton picture have been implemented for time-dependent density functional theory. State characters such as local, extended ππ∗, Rydberg, or charge transfer can be intuitively classified by simple comparison of these descriptors. Strong effects of the choice of the exchange-correlation kernel on the physical nature of excited states can be found and decomposed in detail leading to a new perspective on functional performance and the design of new functionals.

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mentioning

confidence: 74%

Communication: Exciton analysis in time-dependent density functional theory: How functionals shape excited-state characters

Mewes

Plasser

Dreuw

2015

The Journal of Chemical Physics

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“…In Fig 1, we plot is a strong function of the exact orbital-dependent exchange (Fock-like exchange) present in the functional [35]. For example, the ZINDO (100% of exact-exchange) curve saturates faster to the constant long-chain-limit than B3LYP (20% of exact-exchange) results.…”

Section: Resultsmentioning

confidence: 99%

A joint theoretical and experimental study of phenylene–acetylene molecular wires

Magyar

Tretiak

Gao

et al. 2005

Chemical Physics Letters

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The excited state electronic structure of π conjugated phenylene-acetylene oligomers is calculated using time-dependent density functional theory (TD-DFT) approaches. The theoretical fluorescence spectra are analyzed in terms of Frank-Condon active nuclear normal modes and shown to compare well with experiment. Theoretical and experimental results for the optical absorption and emission spectra of these molecules indicate that the conjugation length can be significantly reduced by conformational rotations about the triple-bonded carbon links. This has serious implications on the electronic functionalities of polyphenylene-acetylene based molecular wires and their possible use as charge/energy conduits in nano-assemblies.

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“…During excited-state geometry optimization the bonds along the conjugated backbone stretch, so that the bond-length alternation caused by uneven distribution of π-electronic density reduces. 28 This allows the electrons to become more delocalized, and the excited-state energy is reduced. The magnitude of the observed Stokes shift and the respective geometry changes intensify with an increase of the fraction of exchange.…”

Section: Resultsmentioning

confidence: 99%

“…With the most commonly used approximate kernels, such as LDA and GGA models, many bound exciton states are not described at all. 27,28 This is because the kernal is local and the orbital overlap is negligible. This problem is further complicated by the neglect of an important derivative discontinuity in most functionals.…”

Section: Introductionmentioning

confidence: 99%

Dependence of Spurious Charge-Transfer Excited States on Orbital Exchange in TDDFT: Large Molecules and Clusters

Magyar

Tretiak

2007

J. Chem. Theory Comput.

301

276

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Time-dependent density functional theory (TDDFT) is a powerful tool allowing for accurate description of excited states in many nanoscale molecular systems; however, its application to large molecules may be plagued with difficulties that are not immediately obvious from previous experiences of applying TDDFT to small molecules. In TDDFT, the appearance of spurious charge-transfer states below the first optical excited state is shown to have significant effects on the predicted absorption and emission spectra of several donor-acceptor substituted molecules. The same problem affects the predictions of electronic spectra of molecular aggregates formed from weakly interacting chromophores. For selected benchmark cases, we show that today's popular density functionals, such as purely local (Local Density Approximation, LDA) and semilocal (Generalized Gradient Approximation, GGA) models, are qualitatively wrong. Nonlocal hybrid approximations including both semiempirical (B3LYP) and ab initio (PBE1PBE) containing a small fraction (20-25%) of Fock-like orbital exchange are also susceptible to such problems. Functionals that contain a larger fraction (50%) of orbital exchange like the early hybrid (BHandHLYP) are shown to exhibit far fewer spurious charge-transfer (CT) states at the expense of accuracy. Based on the trends observed in this study and our previous experience we formulate several practical approaches to overcome these difficulties providing a reliable description of electronic excitations in nanosystems.

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Exciton sizes of conducting polymers predicted by time-dependent density functional theory

Cited by 205 publications

References 30 publications

Communication: Exciton analysis in time-dependent density functional theory: How functionals shape excited-state characters

Communication: Exciton analysis in time-dependent density functional theory: How functionals shape excited-state characters

A joint theoretical and experimental study of phenylene–acetylene molecular wires

Dependence of Spurious Charge-Transfer Excited States on Orbital Exchange in TDDFT: Large Molecules and Clusters

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