Spin-Vibronic Quantum Dynamics for Ultrafast Excited-State Processes

2015 ◽  
Vol 48 (3) ◽  
pp. 809-817 ◽  
Author(s):  
Julien Eng ◽  
Christophe Gourlaouen ◽  
Etienne Gindensperger ◽  
Chantal Daniel
Keyword(s):  
Excited State ◽  
Quantum Dynamics

scholarly journals Photophysics of a copper phenanthroline elucidated by trajectory and wavepacket-based quantum dynamics: a synergetic approach

2017 ◽  
Vol 19 (30) ◽  
pp. 19590-19600 ◽  
Author(s):  
G. Capano ◽  
T. J. Penfold ◽  
M. Chergui ◽  
I. Tavernelli
Keyword(s):  
Molecular Dynamics ◽  
Excited State ◽  
Excited States ◽  
Ground State ◽  
Quantum Dynamics ◽  
Equilibrium Processes ◽  
Valuable Method ◽  
Non Equilibrium

On-the-fly excited state molecular dynamics is a valuable method for studying non-equilibrium processes in excited states and is beginning to emerge as a mature approach much like its ground state counterparts.

scholarly journals Excited state non-adiabatic dynamics of pyrrole: A time-resolved photoelectron spectroscopy and quantum dynamics study

2015 ◽  
Vol 142 (7) ◽  
pp. 074302 ◽  
Author(s):  
Guorong Wu ◽  
Simon P. Neville ◽  
Oliver Schalk ◽  
Taro Sekikawa ◽  
Michael N. R. Ashfold ◽  
...  
Keyword(s):  
Excited State ◽  
Photoelectron Spectroscopy ◽  
Quantum Dynamics ◽  
Time Resolved ◽  
Adiabatic Dynamics

A Tiny Excited-State Barrier Can Induce a Multiexponential Decay of the Retinal Chromophore: A Quantum Dynamics Investigation

2005 ◽  
Vol 117 (32) ◽  
pp. 5248-5251 ◽  
Author(s):  
Massimo Olivucci ◽  
Alessandro Lami ◽  
Facrizio Santoro
Keyword(s):  
Excited State ◽  
Quantum Dynamics ◽  
Retinal Chromophore

scholarly journals Excited state non-adiabatic dynamics of N-methylpyrrole: A time-resolved photoelectron spectroscopy and quantum dynamics study

2016 ◽  
Vol 144 (1) ◽  
pp. 014309 ◽  
Author(s):  
Guorong Wu ◽  
Simon P. Neville ◽  
Oliver Schalk ◽  
Taro Sekikawa ◽  
Michael N. R. Ashfold ◽  
...  
Keyword(s):  
Excited State ◽  
Photoelectron Spectroscopy ◽  
Quantum Dynamics ◽  
Time Resolved ◽  
Adiabatic Dynamics

Quantum Dynamics of the Excited-State Intramolecular Proton Transfer in 2-(2′-Hydroxyphenyl)benzothiazole

2009 ◽  
Vol 49 (2) ◽  
pp. 187-197 ◽  
Author(s):  
Justin Kim ◽  
Yinghua Wu ◽  
Jean-Luc Brédas ◽  
Victor S. Batista
Keyword(s):  
Excited State ◽  
Proton Transfer ◽  
Quantum Dynamics ◽  
Intramolecular Proton Transfer

scholarly journals Towards Prediction of Non-Radiative Decay Pathways in Organic Compounds I: The Case of Naphthalene Quantum Yields

2019 ◽  
Author(s):  
Alexander Kohn ◽  
Zhou Lin ◽  
Troy Van Voorhis
Keyword(s):  
Machine Learning ◽  
Excited State ◽  
Quantum Yield ◽  
Quantum Dynamics ◽  
Density Functional ◽  
Rational Design ◽  
Radiative Decay ◽  
Quantum Yields ◽  
Equilibrium Geometry ◽  
Radiative Loss

<div>Many emerging technologies depend on human’s ability to control and manipulate the excited-state properties of molecular systems. These technologies include fluorescent</div><div>labeling in biomedical imaging, light harvesting in photovoltaics, and electroluminescence in light-emitting devices. All of these systems suffer from non-radiative loss pathways that dissipate electronic energy as heat, which causes the overall system efficiency to be directly linked to quantum yield (Φ) of the molecular excited state. Unfortunately, Φ is very difficult to predict from first principles because the description of a slow non-radiative decay mechanism requires an accurate description of long-timescale excited-state quantum dynamics. In the present study, we introduce an efficient semiempirical method of calculating the fluorescence quantum yield (Φ<sub>fl</sub>) for molecular chromophores, which, based on machine learning, converts simple electronic energies computed using time-dependent density functional theory (TDDFT) into an estimate of Φ<sub>fl</sub>. As with all machine learning strategies, the algorithm needs to be trained on fluorescent dyes for which Φ<sub>fl</sub>’s are known, so as to provide a black-box method which can later predict Φ<sub>fl</sub>’s for chemically similar chromophores that have not been studied experimentally. As a first illustration of how our proposed algorithm can be trained, we examine a family of 25 naphthalene derivatives. The simplest application of the energy gap law is found to be inadequate to explain the rates of internal conversion (IC) or intersystem crossing (ISC) – the electronic properties of at least one higher-lying electronic state (S<i><sub>n</sub></i> or T<i><sub>n</sub></i>) or one far-from-equilibrium geometry are typically needed to obtain accurate results. Indeed, the key descriptors turn out to be the transition state between the Franck–Condon minimum a distorted local minimum near an S<sub>0</sub>/S<sub>1</sub> conical intersection (which governs IC) and the magnitude of the spin–orbit coupling (which governs ISC). The resulting Φ<sub>fl</sub>’s are predicted with reasonable accuracy (±22%), making our approach a promising ingredient for high-throughput screening and rational design of the molecular excited states with desired Φ’s. We thus conclude that our model, while semi-empirical in nature, does in fact extract sound physical insight into the challenge of describing non-radiative relaxations.</div>

scholarly journals Micro-Solvated DMABN: Excited State Quantum Dynamics and Dual Fluorescence Spectra

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7247
Author(s):  
Sandra Gómez ◽  
Esra N. Soysal ◽  
Graham A. Worth
Keyword(s):  
Electronic Structure ◽  
Excited State ◽  
Quantum Dynamics ◽  
Computational Study ◽  
Water Solution ◽  
Fluorescence Emission ◽  
Spectroscopic Properties ◽  
Complete Analysis ◽  
Solvent Molecules ◽  
Dynamics Simulations

In this work, we report a complete analysis by theoretical and spectroscopic methods of the short-time behaviour of 4-(dimethylamino)benzonitrile (DMABN) in the gas phase as well as in cyclohexane, tetrahydrofuran, acetonitrile, and water solution, after excitation to the La state. The spectroscopic properties of DMABN were investigated experimentally using UV absorption and fluorescence emission spectroscopy. The computational study was developed at different electronic structure levels and using the Polarisable Continuum Model (PCM) and explicit solvent molecules to reproduce the solvent environment. Additionally, excited state quantum dynamics simulations in the diabatic picture using the direct dynamics variational multiconfigurational Gaussian (DD-vMCG) method were performed, the largest quantum dynamics “on-the-fly” simulations performed with this method until now. The comparison with fully converged multilayer multiconfigurational time-dependent Hartree (ML-MCTDH) dynamics on parametrised linear vibronic coupling (LVC) potentials show very similar population decays and evolution of the nuclear wavepacket. The ring C=C stretching and three methyl tilting modes are identified as the responsible motions for the internal conversion from the La to the Lb states. No major differences are observed in the ultrafast initial decay in different solvents, but we show that this effect depends strongly on the level of electronic structure used.

scholarly journals Modern Theoretical Approaches to Modeling the Excited-State Intramolecular Proton Transfer: An Overview

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5140 ◽  
Author(s):  
Joanna Jankowska ◽  
Andrzej L. Sobolewski
Keyword(s):  
Excited State ◽  
Proton Transfer ◽  
Quantum Dynamics ◽  
Intramolecular Proton Transfer ◽  
Experimental Investigations ◽  
Chemical Methods ◽  
Theoretical Approaches ◽  
Quantum Chemical Methods ◽  
Process Studies ◽  
Different Levels

The excited-state intramolecular proton transfer (ESIPT) phenomenon is nowadays widely acknowledged to play a crucial role in many photobiological and photochemical processes. It is an extremely fast transformation, often taking place at sub-100 fs timescales. While its experimental characterization can be highly challenging, a rich manifold of theoretical approaches at different levels is nowadays available to support and guide experimental investigations. In this perspective, we summarize the state-of-the-art quantum-chemical methods, as well as molecular- and quantum-dynamics tools successfully applied in ESIPT process studies, focusing on a critical comparison of their specific properties.

Competition between the heavy atom effect and vibronic coupling in donor–bridge–acceptor organometallics

2020 ◽  
Vol 22 (8) ◽  
pp. 4659-4667 ◽  
Author(s):  
Julien Eng ◽  
Stuart Thompson ◽  
Heather Goodwin ◽  
Dan Credgington ◽  
Thomas James Penfold
Keyword(s):  
Excited State ◽  
Quantum Dynamics ◽  
Heavy Atom ◽  
Vibronic Coupling ◽  
Intersystem Crossing ◽  
Heavy Atom Effect ◽  
Metal Amides ◽  
Coinage Metals ◽  
Dynamics Simulations ◽  
Atom Effect

The excited state properties and intersystem crossing dynamics of a series of donor–bridge–acceptor carbene metal-amides based upon the coinage metals Cu, Ag, Au, are investigated using quantum dynamics simulations and supported by photophysical characterisation.

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