Charge transport in organic semiconductors from the mapping approach to surface hopping DOI Creative Commons
Johan E. Runeson,

Thomas J. G. Drayton,

David E. Manolopoulos

et al.

The Journal of Chemical Physics, Journal Year: 2024, Volume and Issue: 161(14)

Published: Oct. 8, 2024

We describe how to simulate charge diffusion in organic semiconductors using a recently introduced mixed quantum-classical method, the mapping approach surface hopping. In contrast standard fewest-switches hopping, this method propagates classical degrees of freedom deterministically on most populated adiabatic electronic state. This correctly preserves equilibrium distribution quantum coupled phonons, allowing one time-average along trajectories improve statistical convergence calculation. illustrate with an application model for transport direction maximum mobility crystalline rubrene. Because its consistency distribution, present gives time-dependent coefficient that plateaus long-time limiting value. The resulting is somewhat higher than relaxation time approximation, which uses phenomenological parameter obtain non-zero from calculation static phonon disorder. However, it very similar obtained Ehrenfest dynamics, at least regimes we have investigated here. surprising because dynamics overheats subsystem and is, therefore, inconsistent distribution.

Language: Английский

Prediction Challenge: Simulating Rydberg photoexcited cyclobutanone with surface hopping dynamics based on different electronic structure methods DOI
Saikat Mukherjee, Rafael S. Mattos, Josene M. Toldo

et al.

The Journal of Chemical Physics, Journal Year: 2024, Volume and Issue: 160(15)

Published: April 16, 2024

This research examines the nonadiabatic dynamics of cyclobutanone after excitation into n → 3s Rydberg S2 state. It stems from our contribution to Special Topic Journal Chemical Physics test predictive capability computational chemistry against unseen experimental data. Decoherence-corrected fewest-switches surface hopping was used simulate with full and approximated couplings. Several simulation sets were computed different electronic structure methods, including a multiconfigurational wavefunction [multiconfigurational self-consistent field (MCSCF)] specially built describe dissociative channels, multireference semiempirical approach, time-dependent density functional theory, algebraic diagrammatic construction, coupled cluster. MCSCF predicts slow deactivation state (10 ps), followed by an ultrafast population transfer S1 S0 (<100 fs). CO elimination (C3 channel) dominates over C2H4 formation (C2 channel). These findings radically differ other which predicted lifetimes 10-250 times shorter C2 channel predominance. results suggest that routine methods may hold low power for outcome dynamics.

Language: Английский

Citations

9
Photoexcited dynamics of the valence states of norbornadiene DOI Creative Commons
Joseph C. Cooper, Crum Brown, Janaka Kara

et al.

The Journal of Chemical Physics, Journal Year: 2025, Volume and Issue: 162(9)

Published: March 3, 2025

The non-radiative decay of photoexcited norbornadiene, which together with its isomer quadricyclane forms a molecular photoswitch, is investigated using surface-hopping non-adiabatic dynamics. simulations are performed four levels electronic structure theory: CASSCF(2,2), CASSCF(4,4), XMS-CASPT2(2,2), and XMS-CASPT2(4,4). These models yield two distinct classes excited-state reaction pathways, different quantum yields for the isomerization. This illustrates significance potential energy surfaces when simulating nature pathways related to topographical features on surfaces, suggesting “design rules” chemical modification via substituent groups. How molecule approaches conical intersection also shown play decisive role in outcome.

Language: Английский

Citations

1
Quantum Quality with Classical Cost: Ab Initio Nonadiabatic Dynamics Simulations Using the Mapping Approach to Surface Hopping DOI Creative Commons
Jonathan R. Mannouch, Aaron Kelly

The Journal of Physical Chemistry Letters, Journal Year: 2024, Volume and Issue: 15(22), P. 5814 - 5823

Published: May 23, 2024

Nonadiabatic dynamics methods are an essential tool for investigating photochemical processes. In the context of employing first-principles electronic structure techniques, such simulations can be carried out in a practical manner using semiclassical trajectory-based or wave packet approaches. While all approaches applicable to necessarily approximate, it is commonly thought that offer inherent advantages over their counterparts terms accuracy and this trait simply comes at higher computational cost. Here we demonstrate mapping approach surface hopping (MASH), recently introduced nonadiabatic method, efficiently applied tandem with

Language: Английский

Citations

8
A size-consistent multi-state mapping approach to surface hopping DOI
Joseph E. Lawrence, Jonathan R. Mannouch, Jeremy O. Richardson

et al.

The Journal of Chemical Physics, Journal Year: 2024, Volume and Issue: 160(24)

Published: June 28, 2024

We develop a multi-state generalization of the recently proposed mapping approach to surface hopping (MASH) for simulation electronically nonadiabatic dynamics. This new extends original MASH method be able treat systems with more than two electronic states. It differs from previous approaches in that it is size consistent and rigorously recovers two-state appropriate limits. demonstrate accuracy by applying series model which exact benchmark results are available, we find well suited photochemical relaxation processes.

Language: Английский

Citations

5
The photochemistry of Rydberg-excited cyclobutanone: Photoinduced processes and ground state dynamics DOI Creative Commons
Julien Eng, Conor D. Rankine, Thomas J. Penfold

et al.

The Journal of Chemical Physics, Journal Year: 2024, Volume and Issue: 160(15)

Published: April 15, 2024

Owing to ring strain, cyclic ketones exhibit complex excited state dynamics with multiple competing photochemical channels active on the ultrafast timescale. While of cyclobutanone after π* ← n excitation into lowest-energy singlet (S1) has been extensively studied, following 3s higher-lying Rydberg (S2) are less well understood. Herein, we employ fully quantum multiconfigurational time-dependent Hartree (MCTDH) simulations using a model Hamiltonian as "on-the-fly" trajectory-based surface-hopping (TSHD) study relaxation and predict electron diffraction scattering signature these dynamics. Our MCTDH TSHD indicate that from initially-populated occurs timescale few hundreds femtoseconds picosecond, consistent symmetry-forbidden nature state-to-state transition involved. There is no obvious involvement triplet states within timeframe our (<2 ps). After non-radiative electronic ground (S0), vibrationally hot sufficient internal energy form fragmented products including C2H4 + CH2CO (C2; 20%) C3H6 CO (C3; 2.5%). We discuss limitations simulations, how may influence observe, and-ultimately-the predictive power simulated experimental observable.

Language: Английский

Citations

4
Time-Reversible Implementation of MASH for Efficient Nonadiabatic Molecular Dynamics DOI Creative Commons

J. Amira Geuther,

Kasra Asnaashari, Jeremy O. Richardson

et al.

Journal of Chemical Theory and Computation, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 25, 2025

In this work, we describe various improved implementations of the mapping approach to surface hopping (MASH) for simulating nonadiabatic dynamics. These include time-reversible and piecewise-continuous integrators, which are only formally possible because deterministic nature underlying MASH equations motion. The new algorithms allow use either wave-function overlaps or coupling vectors propagate spin, encodes electronic state. For a given time-step, Δt, it is demonstrated that global error these methods O(Δt2) compared O(Δt) standard implementations. This allows larger time-steps be used desired tolerance, conversely, more accurate observables fixed value Δt. newly developed integrators thus provide further advantages method, demonstrating can implemented efficiently than other surface-hopping approaches, cannot construct due their stochastic nature.

Language: Английский

Citations

0
Imaging the photochemical dynamics of cyclobutanone with MeV ultrafast electron diffraction DOI
Tianyu Wang, Hui Jiang, Cheng Jin

et al.

The Journal of Chemical Physics, Journal Year: 2025, Volume and Issue: 162(18)

Published: May 8, 2025

We study the photoinduced chemical dynamics of cyclobutanone upon excitation at 200 nm to 3s Rydberg state using MeV ultrafast electron diffraction (UED). observe both elastic scattering signal, which contains information about structural dynamics, and inelastic encodes electronic state. Our results suggest a sub-picosecond timescale for photodissociation an excited lifetime 230 femtoseconds. The dissociation is found be dominated by C3 channel, where cyclopropane CO are produced. branching ratio channel C2 ethene ketene produced, estimated ∼5:3. data that channels account ∼80% photoproducts, with remaining 20% exhibiting ring-opened structures. It associated process in shorter compared channel. Leveraging enhanced temporal resolution UED, our provide real-time mapping nuclear wave packet capturing complete photochemical from S2 minimum through S1/S0 conical intersection finally dissociation. experimental new insights into Norrish type I reaction can used benchmark non-adiabatic simulations.

Language: Английский

Citations

0
Imaging the photochemistry of cyclobutanone using ultrafast electron diffraction: Experimental results DOI
Alice Green, Yusong Liu, Felix Allum

et al.

The Journal of Chemical Physics, Journal Year: 2025, Volume and Issue: 162(18)

Published: May 12, 2025

We investigated the ultrafast structural dynamics of cyclobutanone following photoexcitation at λ = 200 nm using gas-phase megaelectronvolt electron diffraction. Our investigation complements simulation studies same process within this special issue. It provides information about both electronic state population and through well-separable inelastic elastic scattering signatures. observe depopulation photoexcited S2 with n3s Rydberg character its signature a time constant (0.29 ± 0.2) ps toward S1 state. The undergoes ring-opening via Norrish Type-I reaction, likely while passing conical intersection S0. corresponding changes can be tracked by These appear delay (0.14 0.05) respect to initial photoexcitation, which is less than constant. This behavior evidence for ballistic nature once reached. resulting biradical species react further (1.2 two rival fragmentation channels yielding ketene ethylene, or propene carbon monoxide. study showcases value diffraction as an experimental benchmark nonadiabatic methods limits in interpretation such data without comparison simulations.

Language: Английский

Citations

0
Charge transport in organic semiconductors from the mapping approach to surface hopping DOI Creative Commons
Johan E. Runeson,

Thomas J. G. Drayton,

David E. Manolopoulos

et al.

The Journal of Chemical Physics, Journal Year: 2024, Volume and Issue: 161(14)

Published: Oct. 8, 2024

We describe how to simulate charge diffusion in organic semiconductors using a recently introduced mixed quantum-classical method, the mapping approach surface hopping. In contrast standard fewest-switches hopping, this method propagates classical degrees of freedom deterministically on most populated adiabatic electronic state. This correctly preserves equilibrium distribution quantum coupled phonons, allowing one time-average along trajectories improve statistical convergence calculation. illustrate with an application model for transport direction maximum mobility crystalline rubrene. Because its consistency distribution, present gives time-dependent coefficient that plateaus long-time limiting value. The resulting is somewhat higher than relaxation time approximation, which uses phenomenological parameter obtain non-zero from calculation static phonon disorder. However, it very similar obtained Ehrenfest dynamics, at least regimes we have investigated here. surprising because dynamics overheats subsystem and is, therefore, inconsistent distribution.

Language: Английский

Citations

2