Nonadiabatic Excited-State Molecular Dynamics Methodologies: Comparison and Convergence

The Journal of Physical Chemistry Letters, Год журнала: 2021, Номер 12(11), С. 2970 - 2982

Опубликована: Март 17, 2021

Direct atomistic simulation of nonadiabatic molecular dynamics is a challenging goal that allows important insights into fundamental physical phenomena. A variety frameworks, ranging from fully quantum treatment nuclei to semiclassical and mixed quantum–classical approaches, were developed. These algorithms are then coupled specific electronic structure techniques. Such diversity lack standardized implementation make it difficult compare the performance different methodologies when treating realistic systems. Here, we three popular methods for large chromophores: Ehrenfest, surface hopping, multiconfigurational Ehrenfest with ab initio multiple cloning (MCE-AIMC). approaches implemented in NEXMD software, which features common computational chemistry model. The resulting comparisons reveal method population relaxation coherent vibronic dynamics. Finally, study numerical convergence MCE-AIMC by considering number trajectories, thresholds, Gaussian wavepacket width. Our results provide helpful reference data selecting an optimal methodology simulating excited-state

Язык: Английский

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PyUNIxMD: A Python‐based excited state molecular dynamics package

Journal of Computational Chemistry, Год журнала: 2021, Номер 42(24), С. 1755 - 1766

Опубликована: Июль 1, 2021

Theoretical/computational description of excited state molecular dynamics is nowadays a crucial tool for understanding light-matter interactions in many materials. Here we present an open-source Python-based nonadiabatic program package, namely PyUNIxMD, to deal with mixed quantum-classical correlated electron-nuclear propagation. The PyUNIxMD provides interfaces quantum chemical calculation methods commercial and noncommercial ab initio semiempirical chemistry programs. In addition, the offers algorithms such as fewest-switch surface hopping its derivatives well decoherence-induced based on exact factorization (DISH-XF) coupled-trajectory (CTMQC) general purposes. Detailed structures flows are explained further implementations by developers. We perform simulation motor system simple demonstration.

Язык: Английский

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Theoretical Advances in Polariton Chemistry and Molecular Cavity Quantum Electrodynamics

Опубликована: Дек. 7, 2022

When molecules are coupled to an optical cavity, new light-matter hybrid states, so-called polaritons, formed due quantum interactions. With the experimental demonstrations of modifying chemical reactivities by forming polaritons under strong interactions, theorists have been encouraged develop methods simulate these systems and discover strategies tune control reactions. This review summarizes some exciting theoretical advances in polariton chemistry, ranging from fundamental framework computational techniques applications spanning photochemistry vibrational coupling. Even though theory interactions goes back mid-twentieth century, gaps knowledge molecular electrodynamics (QED) only recently filled. We recent made resolving gauge ambiguities, correct form different QED Hamiltonians gauges, their connections various optics models. Then, we developed {\it ab-initio} approaches which can accurately describe states a realistic molecule-cavity system. then discuss using method advancements. advancements where cavity is resonant electronic transitions non-adiabatic excited state dynamics enable photochemical reactivities. resonance tuned vibrations instead, ground-state reaction modifications demonstrated experimentally, its mechanistic principle remains unclear. present progress this mystery. Finally, understanding collective coupling regime between light matter, many collectively couple single mode or modes. also lay out current challenges explain observed results. hope that will serve as useful document for anyone who wants become familiar with context chemistry thus significantly benefit entire community.

Язык: Английский

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NWChem: Recent and Ongoing Developments

Journal of Chemical Theory and Computation, Год журнала: 2023, Номер 19(20), С. 7077 - 7096

Опубликована: Июль 17, 2023

This paper summarizes developments in the NWChem computational chemistry suite since last major release (NWChem 7.0.0). Specifically, we focus on functionality, along with input blocks, that is accessible current stable 7.2.0) and "master" development branch, interfaces to quantum computing simulators, external libraries, github repository, containerization of executable images. Some ongoing will be available near future are also discussed.

Язык: Английский

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Libra: A modular software library for quantum nonadiabatic dynamics

Software Impacts, Год журнала: 2022, Номер 14, С. 100445 - 100445

Опубликована: Ноя. 17, 2022

Язык: Английский

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Nonadiabatic Molecular Dynamics with Extended Density Functional Tight-Binding: Application to Nanocrystals and Periodic Solids

Journal of Chemical Theory and Computation, Год журнала: 2022, Номер 18(9), С. 5157 - 5180

Опубликована: Июнь 27, 2022

In this work, we report a new methodology for nonadiabatic molecular dynamics calculations within the extended tight-binding (xTB) framework. We demonstrate applicability of developed approach to finite and periodic systems with thousands atoms by modeling "hot" electron relaxation in silicon nanocrystals electron-hole recombination both graphitic carbon nitride monolayer titanium-based metal-organic framework (MOF). This work reports dynamic simulations largest Si studied so far xTB framework, diameters up 3.5 nm. For nanocrystals, find non-monotonic dependence rates on nanocrystal size, agreement available experimental reports. rationalize relationship combination decreasing couplings related system size increase coherent transfer pathways higher densities states. emphasize importance proper treatment coherences obtaining such dependences. characterize Ti-containing MOF. spin-adaptation sampling surface hopping trajectories processes. also assess several trajectory schemes highlight their distinct qualitative behavior excited-state superexchange-like models depending how they handle between nearly parallel

Язык: Английский

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First Principles Nonadiabatic Excited-State Molecular Dynamics in NWChem

Journal of Chemical Theory and Computation, Год журнала: 2020, Номер 16(10), С. 6418 - 6427

Опубликована: Авг. 18, 2020

Computational simulation of nonadiabatic molecular dynamics is an indispensable tool for understanding complex photoinduced processes such as internal conversion, energy transfer, charge separation, and spatial localization excitons, to name a few. We report implementation the fewest-switches surface-hopping algorithm in NWChem computational chemistry program. The method combined with linear-response time-dependent density functional theory calculations adiabatic excited-state potential surfaces. To treat quantum transitions between arbitrary electronic Born-Oppenheimer states, we have implemented both numerical analytical differentiation schemes derivative couplings. A approach time-derivative couplings together calculating coupling vectors efficient combination approaches. Additionally, decoherence state reassigned unavoided crossings are improve accuracy simulated handle trivial crossings. apply our code study ultrafast decay photoexcited benzene, including detailed analysis surface, population timescales, vibrational coordinates coupled excitation dynamics. also trans-distyrylbenzene. This provides baseline future implementations higher-level frameworks simulating NWChem.

Язык: Английский

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Molecular dynamics study of plasmon-mediated chemical transformations

Chemical Science, Год журнала: 2023, Номер 14(18), С. 4714 - 4723

Опубликована: Янв. 1, 2023

Heterogeneous catalysis of adsorbates on metallic surfaces mediated by plasmons has potential high photoelectric conversion efficiency and controllable reaction selectivity. Theoretical modeling dynamical processes enables in-depth analyses complementing experimental investigations. Especially for plasmon-mediated chemical transformations, light absorption, conversion, electron-electron scattering, electron-phonon coupling occur simultaneously different timescales, making it very challenging to delineate the complex interplay factors. In this work, a trajectory surface hopping non-adiabatic molecular dynamics method is used investigate plasmon excitation in an Au20-CO system, including hot carrier generation, energy relaxation, CO activation induced electron-vibration coupling. The electronic properties indicate that when excited, partial charge transfer takes place from Au20 CO. On other hand, simulations show carriers generated after back forth between Meanwhile, C-O stretching mode activated due couplings. transformations (∼40%) obtained based ensemble average these quantities. Our provide important atomistic insights into perspective simulations.

Язык: Английский

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Dependence of Electron–Hole Recombination Rates on Charge Carrier Concentration: A Case Study of Nonadiabatic Molecular Dynamics in Graphitic Carbon Nitride Monolayers

The Journal of Physical Chemistry C, Год журнала: 2023, Номер 127(19), С. 9083 - 9096

Опубликована: Май 3, 2023

Through systematic nonadiabatic molecular dynamics (NA-MD) calculations in a prototypical graphitic carbon nitride (C3N4) monolayer, we demonstrate strong dependence of electron–hole recombination time scales on the size simulation supercell and hence formal concentration charge carriers. Using our recently developed NA-MD methodology with extended tight-binding electronic structure calculations, have been able to conduct such C3N4 monolayers containing up 5600 atoms. The predicted vary from 7 ps smallest (2 × 2) systems 23 ns largest (8 8, 10 10) ones depend basis excitations used. becomes negligible only very large systems, as 8 or supercells. In this limit, also become insensitive number used inclusion decoherence effects. We propose an effective state reduction model explain result.

Язык: Английский

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Excitation energy transfer and vibronic relaxation through light-harvesting dendrimer building blocks: A nonadiabatic perspective

The Journal of Chemical Physics, Год журнала: 2024, Номер 160(10)

Опубликована: Март 11, 2024

The light-harvesting excitonic properties of poly(phenylene ethynylene) (PPE) extended dendrimers (tree-like π-conjugated macromolecules) involve a directional cascade local excitation energy transfer (EET) processes occurring from the "leaves" (shortest branches) to "trunk" (longest branch), which can be viewed vibronic perspective as sequence internal conversions among connected graph nonadiabatically coupled locally excited electronic states via conical intersections. smallest PPE building block that is able exhibit EET, asymmetrically meta-substituted oligomer with one acetylenic bond on side and two parallel ones other (hence, 2-ring 3-ring para-substituted pseudo-fragments), prototype focus present work. From linear-response time-dependent density functional theory electronic-structure calculations molecule regards its first coupled, optically active, singlet states, we built (1 + 2)-state-8-dimensional vibronic-coupling Hamiltonian model for running subsequent multiconfiguration Hartree wavepacket relaxations propagations, yielding both steady-state absorption emission spectra well real-time dynamics. EET process shortest branch longest occurs quite efficiently (about 80% quantum yield) within 25 fs after light mediated vibrationally through quinoidal bond-stretching modes together particular role given central-ring anti-quinoidal rock-bending mode. Electronic vibrational relaxations, redistributions populations coherences, are interpreted herein lens nonadiabatic perspective, showing some interesting segregation foremost photoactive degrees freedom spectroscopy reactivity.

Язык: Английский

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