A5058593853- Spectroscopy and Quantum Chemical Studies
- Advanced Chemical Physics Studies
- Photochemistry and Electron Transfer Studies
- Mass Spectrometry Techniques and Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Molecular spectroscopy and chirality
- Laser-Matter Interactions and Applications
- Atmospheric Ozone and Climate
- Molecular Junctions and Nanostructures
- Spectroscopy and Laser Applications
- Molecular Spectroscopy and Structure
- Quantum chaos and dynamical systems
- Electron and X-Ray Spectroscopy Techniques
- DNA and Nucleic Acid Chemistry
- Laser Design and Applications
- Quantum, superfluid, helium dynamics
- Strong Light-Matter Interactions
- Building Energy and Comfort Optimization
- Radical Photochemical Reactions
- Nonlinear Dynamics and Pattern Formation
- Radiative Heat Transfer Studies
- Atmospheric chemistry and aerosols
- CO2 Reduction Techniques and Catalysts
- Atomic and Molecular Physics
- Photosynthetic Processes and Mechanisms
Institut de Chimie
2022-2025
Université Paris-Saclay
2023-2025
Centre National de la Recherche Scientifique
2023-2025
Laboratoire de Chimie Physique
2023-2025
Durham University
2019-2022
Instituto de Física Teórica
2019
Faculty (United Kingdom)
2019
University of Vienna
2019
In this work, we present the first implementation of coupled-trajectory Tully surface hopping (CT-TSH) suitable for applications to molecular systems. We combine CT-TSH with semiempirical floating occupation orbital-configuration interaction electronic structure method investigate photoisomerization dynamics trans-azobenzene. Our study shows that can capture correctly decoherence effects in system, yielding consistent and nuclear agreement (standard) decoherence-corrected TSH. Specifically,...
Identifying multiple rival reaction products and transient species formed during ultrafast photochemical reactions determining their time-evolving relative populations are key steps toward understanding predicting outcomes. Yet, most contemporary studies struggle with clearly identifying quantifying competing molecular structures/species among the emerging products. Here, we show that mega-electronvolt electron diffraction in combination ab initio dynamics calculations offer a powerful route...
We present a series of standardized molecular tests for nonadiabatic dynamics, reminiscent the one-dimensional Tully models proposed in 1990.
We present a detailed study of the decoherence correction to surface hopping that was recently derived from exact factorization approach. Ab initio multiple spawning calculations use same initial conditions and electronic structure method are used as reference for three molecules: ethylene, methaniminium cation, fulvene, which nonadiabatic dynamics follows photoexcitation. A comparison with Granucci–Persico energy-based augmented fewest-switches surface-hopping scheme shows...
We introduce an interface between PySpawn, a simulation package to run ab initio multiple spawning (AIMS) nonadiabatic dynamics, and OpenMolcas, software perform multiconfigurational perturbations theory (CASPT2) electronic structure calculations. Our allows us exploit all the functionalities of two codes: modular efficient Python implementation AIMS algorithm extensive analysis tools offered by with cutting-edge CASPT2 equations in including recently introduced analytical gradients...
The Born-Oppenheimer picture has forged our representation and interpretation of photochemical processes, from photoexcitation down to the passage through a conical intersection, funnel connecting different electronic states. In this work, we analyze full in silico experiment, explicit excitation by laser pulse formation photoproducts following nonradiative decay contrasting offered that proposed exact factorization. factorization offers an alternative understanding photochemistry does not...
The observable nature of topological phases related to conical intersections in molecules is studied. Topological should be ubiquitous molecular processes, but their elusive character has often made them a topic discussion. To shed some light on this issue, we simulate the dynamics governed by Jahn-Teller Hamiltonian and analyze it employing two theoretical representations wave function: adiabatic exact factorization. We find fundamental differences between effects arising exclusively...
Volatile organic compounds (VOCs) are ubiquitous atmospheric molecules that generate a complex network of chemical reactions in the troposphere, often triggered by absorption sunlight. Understanding VOC composition atmosphere relies on our ability to characterize all their possible reaction pathways. When considering (transient) VOCs with sunlight, availability photolysis rate constants, utilized general models, is out experimental reach due unstable nature these molecules. Here, we show how...
The ultrafast time evolution of a single-stranded adenine DNA is studied using hybrid multiscale quantum mechanics/molecular mechanics (QM/MM) scheme coupled to nonadiabatic surface hopping dynamics. As model, we use (dA)20 where stacked tetramer treated chemically. dynamical simulations combined with on-the-fly quantitative wave function analysis evidence the nature long-lived electronically excited states formed upon absorption UV light. After rapid decrease initially excitons, relaxation...
Ab Initio Multiple Spawning (AIMS) simulates the excited-state dynamics of molecular systems by representing nuclear wavepackets in a basis coupled traveling Gaussian functions, called trajectory functions (TBFs). New TBFs are spawned when enter regions strong nonadiabaticity, permitting description non-Born–Oppenheimer processes. The spawning algorithm is simultaneously blessing and curse AIMS method: it allows for an accurate transfer amplitude between different electronic states, but also...
Simulating the coupled electronic and nuclear response of a molecule to light excitation requires application nonadiabatic molecular dynamics. However, when faced with specific photophysical or photochemical problem, selecting most suitable theoretical approach from wide array available techniques is not trivial task. The challenge further complicated by lack systematic method comparisons rigorous testing on realistic systems. This absence comprehensive benchmarks remains major obstacle...
We investigate the performance of coupled-trajectory methods for nonadiabatic molecular dynamics in simulating photodynamics 4-(dimethylamino)benzonitrile (DMABN) and fulvene, with electronic structure provided by linear vibrational coupling models. focus on mixed quantum-classical (CTMQC) algorithm (combined) Tully surface hopping [(C)CTTSH] comparison to independent-trajectory approaches, such as multi-trajectory Ehrenfest hopping. Our analysis includes not only populations but also...
Through approximating electron-nuclear correlation terms in the exact factorization approach, trajectory-based methods have been derived and successfully applied to dynamics of a variety light-induced molecular processes, capturing quantum (de)coherence effects rigorously. These account for coupling among trajectories, recovering nonlocal nature nuclear that is completely overlooked traditional independent-trajectory algorithms. Nevertheless, some approximations introduced derivation these...
We study low-energy dynamics generated by a two-dimensional two-state Jahn-Teller Hamiltonian in the vicinity of conical intersection using quantum wave packet and trajectory dynamics. Recently, these were studied comparing adiabatic representation exact factorization, with purpose to highlight different nature topological-phase geometric-phase effects arising two theoretical representations same problem. Here, we employ factorization understand how accurately model an approximate...
To simulate a 200 nm photoexcitation in cyclobutanone to the n-3s Rydberg state, classical trajectories were excited from Wigner distribution singlet state manifold based on excitation energies and oscillator strengths. Twelve 12 triplet states are treated using TD-B3LYP-D3/6-31+G** for electronic structure, nuclei propagated with Tully surface hopping method. Using time-dependent density functional theory, we able predict bond cleavage that takes place S1 as well ultrafast deactivation nπ*....
Simulating the dynamics of a molecule initiated in an excited electronic state constitutes rather challenging task for theoretical and computational chemistry, as such leads to strong coupling between nuclear motion states, that is, breakdown Born–Oppenheimer approximation. This New Views article proposes brief overview on recent developments aiming at simulating excited-state molecules – nonadiabatic molecular focusing particular strategies employing travelling basis functions portray...
This Perspective offers an overview on the applications of exact factorization electron-nuclear wavefunction to domain theoretical photochemistry, where aim is gain insights into ultrafast dynamics molecular systems via simulations their excited-state beyond Born-Oppenheimer approximation. The fac- torization alternative viewpoint Born-Huang representation for interpretation dynamical processes involving electronic ground and excited states as well nonadiabatic coupling through nuclear...
We introduce an interface between PySpawn, a simulation package to run ab initio multiple spawning (AIMS) nonadiabatic dynamics, and OpenMolcas, software perform multiconfigurational perturbations theory (CASPT2) electronic structure calculations. Our allows us exploit all the functionalities of two codes: modular efficient Python implementation AIMS algorithm extensive analysis tools offered by with cutting-edge CASPT2 equations in including recently introduced analytical gradients...
The deactivation dynamics of 1,1-difluoroethylene after light excitation is studied within the surface hopping formalism in presence 3s and 3p Rydberg states using multi-state second order perturbation theory (MS-CASPT2).
Full multiple spawning (FMS) offers an exciting framework for the development of strategies to simulate excited-state dynamics molecular systems. FMS proposes depict nuclear wavepackets by using a growing set traveling multidimensional Gaussian functions called trajectory basis (TBFs). Perhaps most recognized method emanating from is so-called ab initio (AIMS). In AIMS, couplings between TBFs-in principle exact in FMS-are approximated allow on-the-fly evaluation required electronic-structure...
Through approximating electron-nuclear correlation terms in the exact factorization approach, trajectory-based methods have been derived and successfully applied to dynamics of a variety light-induced molecular processes, capturing quantum (de)coherence effects rigorously. These account for coupling among trajectories, recovering non-local nature nuclear which is completely overlooked traditional independent-trajectory algorithms. Nevertheless, some approximations introduced derivation these...