Overture Introducing Vibronic Couplings

1989 ◽  
pp. 1-5
Author(s):  
C. J. Ballhausen
Keyword(s):  
Vibronic Couplings

Analysis of the Bath Motion in the MM-SQC Dynamics Using Unsupervised Machine Learning Dimensionality Reduction Approaches: Principal Component Analysis

2020 ◽  
Author(s):  
Jiawei Peng ◽  
Yu Xie ◽  
Deping Hu ◽  
Zhenggang Lan
Keyword(s):  
Machine Learning ◽  
Principal Component Analysis ◽  
Collective Motion ◽  
Principal Component ◽  
Component Analysis ◽  
Nonadiabatic Dynamics ◽  
Trajectory Data ◽  
Unsupervised Machine Learning ◽  
Physical Knowledge ◽  
Vibronic Couplings

The system-plus-bath model is an important tool to understand nonadiabatic dynamics for large molecular systems. The understanding of the collective motion of a huge number of bath modes is essential to reveal their key roles in the overall dynamics. We apply the principal component analysis (PCA) to investigate the bath motion based on the massive data generated from the MM-SQC (symmetrical quasi-classical dynamics method based on the Meyer-Miller mapping Hamiltonian) nonadiabatic dynamics of the excited-state energy transfer dynamics of Frenkel-exciton model. The PCA method clearly clarifies that two types of bath modes, which either display the strong vibronic couplings or have the frequencies close to electronic transition, are very important to the nonadiabatic dynamics. These observations are fully consistent with the physical insights. This conclusion is obtained purely based on the PCA understanding of the trajectory data, without the large involvement of pre-defined physical knowledge. The results show that the PCA approach, one of the simplest unsupervised machine learning methods, is very powerful to analyze the complicated nonadiabatic dynamics in condensed phase involving many degrees of freedom.

Quantum yield in blue-emitting anthracene derivatives: vibronic coupling density and transition dipole moment density

2014 ◽  
Vol 16 (27) ◽  
pp. 14244-14256 ◽  
Author(s):  
Motoyuki Uejima ◽  
Tohru Sato ◽  
Daisuke Yokoyama ◽  
Kazuyoshi Tanaka ◽  
Jong-Wook Park
Keyword(s):  
Dipole Moment ◽  
Quantum Yield ◽  
Transition Dipole Moment ◽  
Vibronic Coupling ◽  
Transition Dipole ◽  
Anthracene Derivatives ◽  
Vibronic Couplings ◽  
Franck Condon

Diagonal vibronic couplings in the Franck–Condon S1 state cause torsional distortion, which gives rise to enhancement of fluorescence with a large transition dipole moment.

Quantum Dynamics of Exciton Transport and Dissociation in Multichromophoric Systems

2021 ◽  
Vol 72 (1) ◽  
pp. 591-616 ◽  
Author(s):  
Wjatscheslaw Popp ◽  
Dominik Brey ◽  
Robert Binder ◽  
Irene Burghardt
Keyword(s):  
Charge Transfer ◽  
Quantum Dynamics ◽  
Low Frequency ◽  
Functional Materials ◽  
Phonon Modes ◽  
Quantum Dynamical ◽  
Exciton Migration ◽  
Exciton Transport ◽  
Charge Transfer Excitons ◽  
Vibronic Couplings

Due to the subtle interplay of site-to-site electronic couplings, exciton delocalization, nonadiabatic effects, and vibronic couplings, quantum dynamical studies are needed to elucidate the details of ultrafast photoinduced energy and charge transfer events in organic multichromophoric systems. In this vein, we review an approach that combines first-principles parameterized lattice Hamiltonians with accurate quantum dynamical simulations using advanced multiconfigurational methods. Focusing on the elementary transfer steps in organic functional materials, we address coherent exciton migration and creation of charge transfer excitons in homopolymers, notably representative of the poly(3-hexylthiophene) material, as well as exciton dissociation at polymer:fullerene heterojunctions. We emphasize the role of coherent transfer, trapping effects due to high-frequency phonon modes, and thermal activation due to low-frequency soft modes that drive a diffusive dynamics.

scholarly journals Vibronic coherence evolution in multidimensional ultrafast photochemical processes

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
James D. Gaynor ◽  
Jason Sandwisch ◽  
Munira Khalil
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Vibrational Spectroscopy ◽  
Low Frequency ◽  
Coherence Transfer ◽  
Transfer Energy ◽  
Electronic Delocalization ◽  
Vibronic States ◽  
High Frequency Vibrations ◽  
Vibronic Couplings

AbstractThe complex choreography of electronic, vibrational, and vibronic couplings used by photoexcited molecules to transfer energy efficiently is remarkable, but an unambiguous description of the temporally evolving vibronic states governing these processes has proven experimentally elusive. We use multidimensional electronic-vibrational spectroscopy to identify specific time-dependent excited state vibronic couplings involving multiple electronic states, high-frequency vibrations, and low-frequency vibrations which participate in ultrafast intersystem crossing and subsequent relaxation of a photoexcited transition metal complex. We discover an excited state vibronic mechanism driving long-lived charge separation consisting of an initial electronically-localized vibrational wavepacket which triggers delocalization onto two charge transfer states after propagating for ~600 femtoseconds. Electronic delocalization consequently occurs through nonadiabatic internal conversion driven by a 50 cm−1 coupling resulting in vibronic coherence transfer lasting for ~1 picosecond. This study showcases the power of multidimensional electronic-vibrational spectroscopy to elucidate complex, non-equilibrium energy and charge transfer mechanisms involving multiple molecular coordinates.

Classification of Dynamic Vibronic Couplings in Vibrational Real-Time Spectra of a Thiophene Derivative by Few-Cycle Pulses†

2007 ◽  
Vol 111 (50) ◽  
pp. 12985-12994 ◽  
Author(s):  
Takayoshi Kobayashi ◽  
Zhuan Wang ◽  
Tetsuo Otsubo
Keyword(s):  
Real Time ◽  
Thiophene Derivative ◽  
Vibronic Couplings
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