Nonadiabatic Field on Quantum Phase Space: A Century after Ehrenfest

The Journal of Physical Chemistry Letters, Год журнала: 2024, Номер 15(2), С. 644 - 658

Опубликована: Янв. 11, 2024

Nonadiabatic transition dynamics lies at the core of many electron/hole transfer, photoactivated, and vacuum field-coupled processes. About a century after Ehrenfest proposed "Phasenraum" theorem, we report conceptually novel trajectory-based nonadiabatic approach, field (NaF), based on generalized exact coordinate-momentum phase space formulation quantum mechanics. It does not employ conventional Born-Oppenheimer or trajectory in coupling region. Instead, NaF equations motion independent involve nuclear force term addition to an adiabatic single electronic state. A few benchmark tests for gas condensed systems indicate that offers practical tool capture correct correlation processes where states remain coupled all time as well asymptotic region vanishes.

Язык: Английский

---

Diabatic States of Molecules

The Journal of Physical Chemistry A, Год журнала: 2022, Номер 126(7), С. 992 - 1018

Опубликована: Фев. 9, 2022

Quantitative simulations of electronically nonadiabatic molecular processes require both accurate dynamics algorithms and electronic structure information. Direct semiclassical is expensive due to the high cost calculations, hence it limited small systems, ensemble averaging, ultrafast processes, and/or methods that are only semiquantitatively accurate. The calculations can be made manageable if analytic fits data, such most conveniently carried out in a diabatic representation because surfaces smooth couplings between states scalar functions. Diabatic representations, unlike adiabatic ones produced by methods, not unique, finding suitable representations often involves time-consuming nonsystematic diabatization steps. biggest drawback using bases large amounts effort perform globally consistent diabatization, one our goals has been develop do this efficiently automatically. In Feature Article, we introduce mathematical framework discuss including adiabatic-to-diabatic transformations recent progress toward goal automatization.

Язык: Английский

---

Nonadiabatic Dynamics Algorithms with Only Potential Energies and Gradients: Curvature-Driven Coherent Switching with Decay of Mixing and Curvature-Driven Trajectory Surface Hopping

Journal of Chemical Theory and Computation, Год журнала: 2022, Номер 18(3), С. 1320 - 1328

Опубликована: Фев. 1, 2022

Direct dynamics by mixed quantum-classical nonadiabatic methods is an important tool for understanding processes involving multiple electronic states. Very often, the computational bottleneck of such direct simulation comes from structure theory. For example, at every time step a trajectory, requires potential energy surfaces, their gradients, and matrix elements coupling surfaces. The need couplings can be alleviated employing derivatives wave functions, which evaluated overlaps functions successive steps. However, evaluation overlap integrals still expensive large systems. In addition, or are not available, algorithms become inapplicable. this work, building on recent work Baeck An, we propose new that only require adiabatic energies gradients. named curvature-driven coherent switching with decay mixing (κCSDM) trajectory surface hopping (κTSH). We show how powerful these in terms computation accuracy as compared to previous algorithms. lowering cost will allow longer trajectories greater ensemble averaging affordable, ability calculate without extends capability classes methods.

Язык: Английский

---

Coherence in Chemistry: Foundations and Frontiers

Chemical Reviews, Год журнала: 2024, Номер 124(21), С. 11641 - 11766

Опубликована: Окт. 23, 2024

Coherence refers to correlations in waves. Because matter has a wave-particle nature, it is unsurprising that coherence deep connections with the most contemporary issues chemistry research (e.g., energy harvesting, femtosecond spectroscopy, molecular qubits and more). But what does word "coherence" really mean context of molecules other quantum systems? We provide review key concepts, definitions, methodologies, surrounding phenomena chemistry, we describe how terms "quantum coherence" refer many different chemistry. Moreover, show these notions are related concept an interference pattern. indeed complex, ambiguous definitions may spawn confusion. By describing contexts for sciences, aim enhance understanding communication this broad active area

Язык: Английский

---

NEXMD v2.0 Software Package for Nonadiabatic Excited State Molecular Dynamics Simulations

Journal of Chemical Theory and Computation, Год журнала: 2023, Номер 19(16), С. 5356 - 5368

Опубликована: Июль 28, 2023

We present NEXMD version 2.0, the second release of (Nonadiabatic EXcited-state Molecular Dynamics) software package. Across a variety new features, v2.0 incorporates implementations two hybrid quantum-classical dynamics methods, namely, Ehrenfest (EHR) and Ab-Initio Multiple Cloning sampling technique for Multiconfigurational quantum (MCE-AIMC or simply AIMC), which are alternative options to previously implemented trajectory surface hopping (TSH) method. To illustrate these methodologies, we outline direct comparison three methods as in same framework, discussing their weaknesses strengths, using modeled photodynamics polyphenylene ethylene dendrimer building block representative example. also describe expanded normal-mode analysis constraints both ground excited states, newly allow deeper main vibrational motions involved vibronic dynamics. Overall, expands range applications larger multichromophore organic molecules photophysical processes involving coherences persistent couplings between electronic states nuclear velocity.

Язык: Английский

---

Ultrafast electron diffraction of photoexcited gas-phase cyclobutanone predicted by ab initio multiple cloning simulations

The Journal of Chemical Physics, Год журнала: 2024, Номер 160(16)

Опубликована: Апрель 25, 2024

We present the result of our calculations ultrafast electron diffraction (UED) for cyclobutanone excited into S2 electronic state, which is based on non-adiabatic dynamics simulations with Ab Initio Multiple Cloning (AIMC) method structure calculated at SA(3)-CASSCF(12,12)/aug-cc-pVDZ level theory. The key features in UED pattern were identified, can be used to distinguish between reaction pathways observed AIMC dynamics, although there a significant overlap representative signals due structural similarity products. compared experiment.

Язык: Английский

---

Nonadiabatic Field: A Conceptually Novel Approach for Nonadiabatic Quantum Molecular Dynamics

Journal of Chemical Theory and Computation, Год журнала: 2025, Номер unknown

Опубликована: Апрель 7, 2025

Reliable trajectory-based nonadiabatic quantum dynamics methods at the atomic/molecular level are critical for practical understanding and rational design of many important processes in real large/complex systems, where dynamical behavior electrons that nuclei coupled. The paper reports latest progress field (NaF), a conceptually novel approach with independent trajectories. Substantially different from mainstreams Ehrenfest-like surface hopping methods, nuclear force NaF involves arising coupling between electronic states, addition to adiabatic contributed by single state. is capable faithfully describing interplay motion broad regime, which covers relevant states keep coupled wide range or all time bifurcation characteristic essential. derived exact generalized phase space formulation coordinate-momentum variables, constraint (CPS) employed discrete electronic-state degrees freedom (DOFs) infinite Wigner used continuous DOFs. We propose efficient integrators equations both diabatic representations. Since formalism CPS not unique, can principle be implemented various representations correlation function (TCF) time-dependent property. They applied suite representative gas-phase condensed-phase benchmark models numerically results available comparison. It shown relatively insensitive representation TCF will potential tool reliable simulations mechanical transition systems.

Язык: Английский

---

Common Defects Accelerate Charge Carrier Recombination in CsSnI₃ without Creating Mid-Gap States

The Journal of Physical Chemistry Letters, Год журнала: 2021, Номер 12(36), С. 8699 - 8705

Опубликована: Сен. 2, 2021

Lead-free metal halide perovskites are environmentally friendly and have favorable electro-optical properties; however, their efficiencies significantly below the theoretical limit. Using ab initio nonadiabatic molecular dynamics, we show that common intrinsic defects accelerate nonradiative charge recombination in CsSnI3 without creating midgap traps. This is contrast to Pb-based perovskites, which many little influence on even prolong carrier lifetimes. Sn-related defects, such as Sn vacancies replacement of with Cs most detrimental, since removal breaks largest number bonds strongly perturbs Sn–I lattice supports carriers. The increase electron-vibrational coupling interact free states. Point associated I atoms less therefore, synthesis should be performed rich conditions. study provides an atomistic rationalization why lead-free exhibits lower photovoltaic efficiency compared some lead-based perovskites.

Язык: Английский

---

Nonadiabatic Dynamics with Coupled Trajectories

Journal of Chemical Theory and Computation, Год журнала: 2021, Номер 17(10), С. 5969 - 5991

Опубликована: Сен. 10, 2021

In this paper, we discuss coupled-trajectory schemes for molecular-dynamics simulations of excited-state processes. New strategies to capture decoherence effects, revival coherence and nonadiabatic interferences in long-time dynamics are proposed, compared independent-trajectory schemes. The working framework is provided by the exact factorization electron–nuclear wave function, it exploits ideas emanating from various surface-hopping new algorithms tested on a one-dimensional two-state system using different model parameters which allow one induce dynamics. benchmark numerically solution time-dependent Schrödinger equation.

Язык: Английский

---

Exciton Dissociation in a Model Organic Interface: Excitonic State-Based Surface Hopping versus Multiconfigurational Time-Dependent Hartree

The Journal of Physical Chemistry Letters, Год журнала: 2022, Номер 13(31), С. 7105 - 7112

Опубликована: Июль 28, 2022

Quantum dynamical simulations are essential for a molecular-level understanding of light-induced processes in optoelectronic materials, but they tend to be computationally demanding. We introduce an efficient mixed quantum-classical nonadiabatic molecular dynamics method termed eXcitonic state-based Surface Hopping (X-SH), which propagates the electronic Schrödinger equation space local excitonic and charge-transfer states, coupled thermal motion nuclear degrees freedom. The is applied exciton decay 1D model fullerene–oligothiophene junction, results compared ones from fully quantum treatment at level Multilayer Multiconfigurational Time-Dependent Hartree (ML-MCTDH) approach. Both methods predict that charge-separated states formed on 10–100 fs time scale via multiple "hot-exciton dissociation" pathways. demonstrate X-SH promising tool advancing simulation photoexcited true nanomaterials scale.

Язык: Английский

---