Davydov-type excitonic effects on the absorption spectra of parallel-stacked and herringbone aggregates of pentacene: Time-dependent density-functional theory and time-dependent density-functional tight binding.

@article{Darghouth2018DavydovtypeEE,
  title={Davydov-type excitonic effects on the absorption spectra of parallel-stacked and herringbone aggregates of pentacene: Time-dependent density-functional theory and time-dependent density-functional tight binding.},
  author={Ala Aldin M. H. M. Darghouth and Gabriela Calinao Correa and Sacha Juillard and Mark E. Casida and Alexander Humeniuk and Roland Mitri{\'c}},
  journal={The Journal of chemical physics},
  year={2018},
  volume={149 13},
  pages={
          134111
        }
}
Exciton formation leads to J-bands in solid pentacene. Describing these exciton bands represents a challenge for both time-dependent (TD) density-functional theory (DFT) and for its semi-empirical analog, namely, for TD density-functional tight binding (DFTB) for three reasons: (i) solid pentacene and pentacene aggregates are bound only by van der Waals forces which are notoriously difficult to describe with DFT and DFTB, (ii) the proper description of the long-range coupling between molecules… 

Impact of Charge-Resonance Excitations on CT-Mediated J-Type Aggregation in Singlet and Triplet Exciton States of Perylene Di-Imide Aggregates: A TDDFT Investigation

The modulation of intermolecular interactions upon aggregation induces changes in excited state properties of organic molecules that can be detrimental for some optoelectronic applications but can be

How Long Do Energy and Charge Transfer Take in a Model Buckminsterfullerene/Pentacene Heterojunction? Assessment of Fewest Switches Time-Dependent Density-Functional Tight-Binding with and without Long-Range Correction

Tully-type mixed time-dependent long-range corrected density-functional tight-binding/classical surface-hopping photodynamics is used to investigate the nature of and time scales for energy and

How the Size and Density of Charge-Transfer Excitons Depend on Heterojunction’s Architecture

We have characterized the size, intensity, density, and distribution of charge-transfer (CT) excitons as a function of the acceptor–donor architecture of prototypical organic interfaces. This

On the Low-Lying Electronically Excited States of Azobenzene Dimers: Transition Density Matrix Analysis

It is found that the transitions to the lowest exciton states of the considered dimers are dominated by local excitations, but charge transfer contributions become sizable for some of the lowest ππ* electronic transitions in stacked and slip-stacked dimers at short intermolecular distances.

Spectra and nature of the electronic states of [1]Benzothieno[3,2-b][1]benzothiophene (BTBT): Single crystal and the aggregates.

Quantum-chemistry calculations performed for the simplest aggregate, isolated dimer showed that its structure is similar to the "herringbone" element in the BTBT crystal unit cell and the lowest electronic excited singlet state of the dimer has the intermolecular charge-transfer character.

Exploring the Concept of Dimerization-Induced Intersystem Crossing: At the Origins of Spin-Orbit Coupling Selection Rules.

A coupled experimental and theoretical analysis of the origin of the unusually large ISC efficiency on a series of such dimers that differ by their nature (covalent or supramolecular) paves the way for new molecular engineering rules for SOC control.

Bright Frenkel Excitons in Molecular Crystals: A Survey

The survey confirms that one-dimensional aggregates are rare in molecular crystals highlighting the need to go beyond the simple low-dimensional models and provides practical guidelines for designing materials with interesting optical properties.

Threshold collision induced dissociation of pyrene cluster cations.

By-product clusters containing dehydrogenated species are found to dissociate at energies comparable to the non-dehydrogenated ones, which shows no evidence for covalent bonds within the clusters.

Triplet dynamic nuclear polarization of nanocrystals dispersed in water at room temperature.

The first example of triplet-DNP in water by downsizing the conventional bulk crystals to nanocrystals is reported, carrying out dynamic nuclear polarization using photo-excited triplet electrons in water.

References

SHOWING 1-10 OF 158 REFERENCES

Long-range correction for tight-binding TD-DFT.

Two improvements to the tight-binding approximation of time-dependent density functional theory (TD-DFTB) are presented, which pave the way for using lc-TD- DFTB to describe the electronic structure of large chromophoric polymers, where uncorrected TD-DF TB fails to describeThe high degree of conjugation and produces spurious low-lying charge transfer states.

Direct calculation of exciton binding energies with time-dependent density-functional theory

Excitons are electron-hole pairs appearing below the band gap in insulators and semiconductors. They are vital to photovoltaics, but are hard to obtain with time-dependent density-functional theory

Extensions of the Time-Dependent Density Functional Based Tight-Binding Approach.

The time-dependent density functional based tight-binding (TD-DFTB) approach is generalized to account for fractional occupations. In addition, an on-site correction leads to marked qualitative and

Optoelectronic and Excitonic Properties of Oligoacenes: Substantial Improvements from Range-Separated Time-Dependent Density Functional Theory

It is shown that conventional hybrid functionals over-delocalize excitons and underestimate quasiparticle energy gaps in the acene systems, and the importance of both a range-separated and asymptotically correct contribution of exchange in TDDFT for investigating optoelectronic and excitonic properties, even for these simple valence excitations.

The calculations of excited-state properties with Time-Dependent Density Functional Theory.

In this tutorial review, we show how Time-Dependent Density Functional Theory (TD-DFT) has become a popular tool for computing the signatures of electronically excited states, and more specifically,

Efficient Calculation of Electronic Absorption Spectra by Means of Intensity-Selected TD-DFTB

During the last two decades density functional based linear response approaches have become the de facto standard for the calculation of optical properties of small and medium-sized molecules. At the

Density-Functional Methods for Excited States

Current status and recent developments in linear response TD-DFT.- Density matrix functional theory (DMFT) and linear response time-dependent DMFT (TD-DMFT) for excited states.- Ensemble DFT for

The nature of singlet excitons in oligoacene molecular crystals.

A theory for polarized absorption in crystalline oligoacenes is presented, which includes Frenkel exciton coupling, the coupling between Frenkel and charge-transfer (CT) excitons, and the coupling of

Excitons in molecular crystals from first-principles many-body perturbation theory: Picene versus pentacene

By solving the first-principles many-body Bethe-Salpeter equation, we compare the optical properties of two prototype and technological relevant organic molecular crystals: picene and pentacene.

Atomistic simulations of complex materials: ground-state and excited-state properties

The present status of development of the density-functional-based tightbinding (DFTB) method is reviewed. As a two-centre approach to densityfunctional theory (DFT), it combines computational
...