An efficient solution to the decoherence enhanced trivial crossing problem in surface hopping

Bai, Xin; Qiu, Jing; Wang, Linjun

doi:10.1063/1.5020693

Cited by 46 publications

(100 citation statements)

References 69 publications

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“…Thereby, whether a surface crossing can be regarded as a trivial crossing depends on the choice of the time step size. In large systems, improper treatment of even one trivial crossing will easily lead to artificial long‐range population transfer, inducing enormous errors …”

Section: Surface Crossings In Extended Systemsmentioning

confidence: 99%

“…Based on Equations and , the wavefunction coefficients in the adiabatic representation can be obtained through the representation transformation

w_{i} (t) = \sum_{j} p_{ji} (boldR (t)) c_{j} (t)

where p ji ( R ( t )) = 〈 ϕ i ( r ; R ( t ))| j 〉 are elements of the transformation matrix. It is straightforward that this representation transformation technique can be adopted directly when the diabatic Hamiltonian is already known . In the literature, many diabatization schemes have been developed .…”

Section: Problem B: Wavefunction Propagationmentioning

confidence: 99%

“…In general, the electronic wavefunction is collapsed to the active state to mimic the decay of the off‐diagonal terms of the reduced density matrix. This procedure has a strong impact on the treatment of complex surface crossings …”

Section: Problem E: Correlation Between Decoherence and Crossing Corrmentioning

confidence: 99%

“…For extended systems with many electronic levels and complex surface crossings, a large time step may induce inaccurate hopping probabilities in certain trivial crossing situations, and thus a wrong active state may be selected by mistake. In this case, if the time evolution of the electronic wavefunction is accurately described, the hopping probabilities still follow the correct population fluxes between states, and thus the trajectory tends to hop back to the correct active state in a short time . When decoherence corrections are implemented, however, this self‐correction mechanism no longer has effect.…”

Section: Problem E: Correlation Between Decoherence and Crossing Corrmentioning

confidence: 99%

“…As the number of surface crossings increases remarkably with the system size, the surface crossing problem has become the key bottleneck that limits the application of surface hopping methods to simulate nonadiabatic dynamics in large systems. Moreover, it has been recently shown that the surface crossing problem is further enhanced when the widely used decoherence correction approaches are implemented . In the literature, different aspects of surface hopping have been extensively reviewed .…”

Section: Introductionmentioning

confidence: 99%

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Surface hopping methods for nonadiabatic dynamics in extended systems

Wang

Qiu

Bai

et al. 2019

WIREs Comput Mol Sci

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The review describes recent method developments toward application of the trajectory surface hopping approach for nonadiabatic dynamics simulations of extended systems. Due to the ease of implementation and good balance between efficiency and reliability, surface hopping has become one of the most widely used mixed quantum‐classical methods for studying general charge and exciton dynamics. In extended systems (e.g., aggregates, polymers, surfaces, interfaces, and solids), however, surface hopping suffers from the difficulty to treat complex surface crossings in the adiabatic representation, and thus the relevant applications have been limited in the past years. The latest studies have allowed us to make a systematic classification of the surface crossings and identify their different influence mechanisms on the traditional surface hopping machinery, including problems related to the phase uncertainty correction of adiabatic states, the wave function propagation, the calculation of hopping probabilities, the velocity adjustment after surface hops, and the artificial long‐range population transfer amplified by decoherence corrections. Elegant solutions to each of these problems have enabled us to get fast time step convergence and size independence even for very large systems with different strengths of electron–phonon couplings. Thereby, the recent theoretical progresses have opened the door to simulate the real‐time and real‐space dynamics (e.g., charge separation, recombination, relaxation, and diffusion) in realistic extended systems, and will generate comprehensive understanding to promote the development of many research fields in chemistry, physics, biology, and material sciences in the near future. This article is categorized under: Structure and Mechanism > Computational Materials Science Theoretical and Physical Chemistry > Reaction Dynamics and Kinetics Theoretical and Physical Chemistry > Statistical Mechanics Molecular and Statistical Mechanics > Molecular Dynamics and Monte‐Carlo Methods

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Section: Surface Crossings In Extended Systemsmentioning

confidence: 99%

“…Based on Equations and , the wavefunction coefficients in the adiabatic representation can be obtained through the representation transformation

w_{i} (t) = \sum_{j} p_{ji} (boldR (t)) c_{j} (t)

Section: Problem B: Wavefunction Propagationmentioning

confidence: 99%

Section: Problem E: Correlation Between Decoherence and Crossing Corrmentioning

confidence: 99%

Section: Problem E: Correlation Between Decoherence and Crossing Corrmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Surface hopping methods for nonadiabatic dynamics in extended systems

Wang

Qiu

Bai

et al. 2019

WIREs Comput Mol Sci

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Charge Transport in Organic Semiconductors: The Perspective from Nonadiabatic Molecular Dynamics

Giannini

Blumberger

2022

Acc. Chem. Res.

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Metrics & MoreArticle Recommendations CONSPECTUS: Organic semiconductors (OSs) are an exciting class of materials that have enabled disruptive technologies in this century including large-area electronics, flexible displays, and inexpensive solar cells. All of these technologies rely on the motion of electrical charges within the material and the diffusivity of these charges critically determines their performance. In this respect, it is remarkable that the nature of the charge transport in these materials has puzzled the community for so many years, even for apparently simple systems such as molecular single crystals: some experiments would better fit an interpretation in terms of a localized particle picture, akin to molecular or biological electron transfer, while others are in better agreement with a wave-like interpretation, more akin to band transport in metals.Exciting recent progress in the theory and simulation of charge carrier transport in OSs has now led to a unified understanding of these disparate findings, and this Account will review one of these tools developed in our laboratory in some detail: direct charge carrier propagation by quantum-classical nonadiabatic molecular dynamics. One finds that even in defect-free crystals the charge carrier can either localize on a single molecule or substantially delocalize over a large number of molecules depending on the relative strength of electronic couplings between the molecules, reorganization, or charge trapping energy of the molecule and thermal fluctuations of electronic couplings and site energies, also known as electron−phonon couplings.Our simulations predict that in molecular OSs exhibiting some of the highest measured charge mobilities to date, the charge carrier forms "flickering" polarons, objects that are delocalized over 10−20 molecules on average and that constantly change their shape and extension under the influence of thermal disorder. The flickering polarons propagate through the OS by short (≈10 fs long) bursts of the wave function that lead to an expansion of the polaron to about twice its size, resulting in spatial displacement, carrier diffusion, charge mobility, and electrical conductivity. Arguably best termed "transient delocalization", this mechanistic scenario is very similar to the one assumed in transient localization theory and supports its assertions. We also review recent applications of our methodology to charge transport in disordered and nanocrystalline samples, which allows us to understand the influence of defects and grain boundaries on the charge propagation.Unfortunately, the energetically favorable packing structures of typical OSs, whether molecular or polymeric, places fundamental constraints on charge mobilities/electronic conductivity compared to inorganic semiconductors, which limits their range of applications. In this Account, we review the design rules that could pave the way for new very high-mobility OS materials and we argue that 2D covalent organic frameworks are one of the most promising candidates t...

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Implementation of Coherent Switching with Decay of Mixing into the SHARC Program

Shu

Zhang

Mai

et al. 2020

J. Chem. Theory Comput.

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Simulation of electronically nonadiabatic dynamics is an important tool for understanding the mechanisms of photochemical and photophysical processes. Two contrasting methods in which the electrons are treated quantum mechanically while the nuclei are treated classically are semiclassical Ehrenfest dynamics and trajectory surface hopping; neither method in its original form includes decoherence. Decoherence in the context of electronically nonadiabatic dynamics refers to the gradual collapse of a coherent quantum mechanical electronic state under the scrutiny of nuclear motion into a mixture of stable pointer states. This is modeled in the coherent switches with decay of mixing (CSDM) method by the decay of the off-diagonal elements of the electronic density matrix. Here, we present an implementation of CSDM in the SHARC program; a key element of the new implementation is the use of a different propagator than that used previously in the ANT program.

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An efficient solution to the decoherence enhanced trivial crossing problem in surface hopping

Cited by 46 publications

References 69 publications

Surface hopping methods for nonadiabatic dynamics in extended systems

Surface hopping methods for nonadiabatic dynamics in extended systems

Charge Transport in Organic Semiconductors: The Perspective from Nonadiabatic Molecular Dynamics

Implementation of Coherent Switching with Decay of Mixing into the SHARC Program

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