MLatom Software Ecosystem for Surface Hopping Dynamics in Python with Quantum Mechanical and Machine Learning Methods

Journal of Chemical Theory and Computation, Год журнала: 2024, Номер 20(12), С. 5043 - 5057

Опубликована: Июнь 5, 2024

We present an open-source MLatom@XACS software ecosystem for on-the-fly surface hopping nonadiabatic dynamics based on the Landau–Zener–Belyaev–Lebedev algorithm. The can be performed via Python API with a wide range of quantum mechanical (QM) and machine learning (ML) methods, including ab initio QM (CASSCF ADC(2)), semiempirical methods (e.g., AM1, PM3, OMx, ODMx), many types ML potentials KREG, ANI, MACE). Combinations also used. While user build their own combinations, we provide AIQM1, which is Δ-learning used out-of-the-box. showcase how AIQM1 reproduces isomerization yield trans-azobenzene at low cost. example scripts that, in dozens lines, enable to obtain final population plots by simply providing initial geometry molecule. Thus, those perform optimization, normal mode calculations, condition sampling, parallel trajectories propagation, analysis, result plotting. Given capabilities MLatom training different models, this seamlessly integrated into protocols building models dynamics. In future, deeper more efficient integration Newton-X will vast functionalities dynamics, such as fewest-switches hopping, facilitate similar workflows API.

Язык: Английский

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Machine learning accelerated nonadiabatic dynamics simulations of materials with excitonic effects

The Journal of Chemical Physics, Год журнала: 2025, Номер 162(2)

Опубликована: Янв. 8, 2025

This study presents an efficient methodology for simulating nonadiabatic dynamics of complex materials with excitonic effects by integrating machine learning (ML) models simplified Tamm–Dancoff approximation (sTDA) calculations. By leveraging ML models, we accurately predict ground-state wavefunctions using unconverged Kohn–Sham (KS) Hamiltonians. These ML-predicted KS Hamiltonians are then employed sTDA-based excited-state calculations (sTDA/ML). The results demonstrate that energies, time-derivative couplings, and absorption spectra from sTDA/ML accurate enough compared those conventional density functional theory based sTDA (sTDA/DFT) Furthermore, sTDA/ML-based molecular simulations on two different systems, namely chloro-substituted silicon quantum dot monolayer black phosphorus, achieve more than 100 times speedup the linear response time-dependent DFT simulations. work highlights potential ML-accelerated studying complicated photoinduced large offering significant computational savings without compromising accuracy.

Язык: Английский

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Multiscale Models for Light-Driven Processes

Annual Review of Physical Chemistry, Год журнала: 2021, Номер 72(1), С. 489 - 513

Опубликована: Фев. 10, 2021

Multiscale models combining quantum mechanical and classical descriptions are a very popular strategy to simulate properties processes of complex systems. Many alternative formulations have been developed, they now available in all the most widely used chemistry packages. Their application study light-driven processes, however, is more recent, some methodological numerical problems yet be solved. This especially case for polarizable formulation these models, recent advances which we review here. Specifically, identify describe important specificities that introduces into both simulation excited-state dynamics modeling excitation energy electron transfer processes.

Язык: Английский

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Electron-Volt Fluctuation of Defect Levels in Metal Halide Perovskites on a 100 ps Time Scale

The Journal of Physical Chemistry Letters, Год журнала: 2022, Номер 13(25), С. 5946 - 5952

Опубликована: Июнь 22, 2022

Metal halide perovskites (MHPs) have gained considerable attention due to their excellent optoelectronic performance, which is often attributed unusual defect properties. We demonstrate that midgap levels can exhibit very large and slow energy fluctuations associated with anharmonic acoustic motions. Therefore, care should be taken classifying MHP defects as deep or shallow, since shallow may become vice versa. As a consequence, charges from escape into bands, light absorption extended longer wavelengths, improving material performance. The phenomenon, demonstrated iodine vacancy in CH3NH3PbI3 using machine learning force field, expected for variety of dopants many MHPs other soft inorganic semiconductors. Since large-scale motions precursors chemical decomposition, known problem MHPs, we propose materials are stiffer than but softer traditional semiconductors, such Si TiO2, simultaneously performance stability.

Язык: Английский

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Spin relaxation of electron and hole polarons in ambipolar conjugated polymers

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Янв. 4, 2024

Abstract The charge-transport properties of conjugated polymers have been studied extensively for opto-electronic device applications. Some polymer semiconductors not only support the ambipolar transport electrons and holes, but do so with comparable carrier mobilities. This opens possibility gaining deeper insight into physics these complex materials via comparison between electron hole dynamics while keeping other factors, such as microstructure, equal. Here, we use field-induced spin resonance spectroscopy to compare relaxation behavior polarons in three polymers. Our experiments show unique regimes a function temperature whereby at lower temperatures relax slower than higher temperatures, so-called spin-shuttling regime, trend is reversed. On basis theoretical simulations, attribute this differences delocalization wavefunctions that shuttling provides sensitive probe intimate coupling charge structural dynamics.

Язык: Английский

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Consistent Construction of the Density Matrix from Surface Hopping Trajectories

Journal of Chemical Theory and Computation, Год журнала: 2024, Номер 20(6), С. 2349 - 2361

Опубликована: Март 16, 2024

Proper construction of the density matrix based on surface hopping trajectories remains a difficult problem. Due to well-known overcoherence in traditional simulations, electronic wave function cannot be used directly. In this work, we propose consistent method, which takes advantage occupation active states rescale coherence calculated by functions and ensures intrinsic consistency matrix. This new trajectory analysis method can for both Tully's fewest switches (FSSH) our recently proposed branching corrected (BCSH). As benchmarked one- two-dimensional standard scattering models, approach combined with BCSH achieves highly accurate time-dependent spatial distributions adiabatic populations compared exact quantum results.

Язык: Английский

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Surface Hopping with Reliable Wave Function by Introducing Auxiliary Wave Packets to Trajectory Branching

The Journal of Physical Chemistry Letters, Год журнала: 2024, Номер 15(12), С. 3345 - 3353

Опубликована: Март 18, 2024

It is well-known that the widely utilized fewest switches surface hopping method suffers from severe overcoherence problem, and thus adiabatic populations calculated by wave functions are generally inferior to those based on active states. More importantly, achieve a complete description of nonadiabatic dynamics, density matrix essential. In this paper, we present an auxiliary branching corrected (A-BCSH) introduces packets (WPs) potential energy surfaces for trajectory branching. Both rapid gradual separation WP components different characterized, correct decoherence time along each captured. As demonstrated in three standard Tully models, A-BCSH exhibits excellent internal consistency. Namely, close obtained both particular, successfully obtains reliable time-dependent spatial distribution matrix, which relies only electronic functions. Due its high performance, our provides new highly promising perspective further development more consistent with function.

Язык: Английский

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Detailed Complementary Consistency: Wave Function Tells Particle How to Hop, Particle Tells Wave Function How to Collapse

The Journal of Physical Chemistry Letters, Год журнала: 2024, Номер 15(26), С. 6771 - 6781

Опубликована: Июнь 24, 2024

In mixed quantum-classical dynamics, the quantum subsystem can have both wave function and particle-like descriptions. However, they may yield inconsistent results for expectation value of same physical quantity. We here propose a novel detailed complementary consistency (DCC) method based on principle internal consistency. Namely, along each trajectory tells particle how to hop, while collapse active states in ensemble. As benchmarked diverse array representative models with localized nonadiabatic couplings, DCC not only achieves fully consistent (i.e., identical populations calculated functions states) but also closely reproduces exact results. Due high performance, our new has great potential give accurate description general dynamics after further development.

Язык: Английский

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Modeling charge transport in high-mobility molecular semiconductors: Balancing electronic structure and quantum dynamics methods with the help of experiments

The Journal of Chemical Physics, Год журнала: 2020, Номер 152(19)

Опубликована: Май 20, 2020

Computing the charge mobility of molecular semiconductors requires a balanced set approximations covering both electronic structure Hamiltonian parameters and modeling dynamics. For problems such complexity, it is hard to make progress without independently validating each layer approximation. In this perspective, we survey how all terms model can be computed validated by independent experiments discuss whether some common made build are valid. We then consider range quantum dynamics approaches used carrier stressing strong weak points method on basis available computational results. Finally, non-trivial aspects novel opportunities related comparison theoretical predictions with recent experimental data.

Язык: Английский

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Design Rules to Maximize Charge-Carrier Mobility along Conjugated Polymer Chains

The Journal of Physical Chemistry Letters, Год журнала: 2020, Номер 11(16), С. 6519 - 6525

Опубликована: Июль 21, 2020

The emergence of polymeric materials displaying high charge-carrier mobility values despite poor interchain structural order has spawned a renewal interest in the identification structure–property relationships pertaining to transport charges along conjugated polymer chains and subsequent design optimized architectures. Here, we present results intrachain charge simulations obtained by applying robust surface hopping algorithm phenomenological Hamiltonian parametrized against first-principles simulations. Conformational effects are shown provide clear signature temperature-dependent that complies with recent experimental observations. We further contrast molecular crystals evolution electronic bandwidth electron–phonon interactions room-temperature polymers, showing excess 100 cm2/(V s) can be achieved through proper chemical engineering backbones.

Язык: Английский

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