High-Fidelity First Principles Nonadiabaticity: Diabatization, Analytic Representation of Global Diabatic Potential Energy Matrices, and Quantum Dynamics

2021 ◽  
Author(s):  
Yafu Guan ◽  
Changjian Xie ◽  
David R. Yarkony ◽  
Hua Guo
Keyword(s):  
Potential Energy ◽  
Excited States ◽  
First Principles ◽  
Quantum Dynamics ◽  
Chemical Processes ◽  
High Fidelity ◽  
Nonadiabatic Dynamics ◽  
Electronically Excited States ◽  
Electronically Excited ◽  
Oppenheimer Approximation

Nonadiabatic dynamics, which goes beyond the Born-Oppenheimer approximation, has increasingly been shown to play an important role in chemical processes, particularly those involving electronically excited states. Understanding multistate dynamics requires...

scholarly journals Stereodynamical Control of Nonadiabatic Quenching Dynamics of OH(A2S+) by H2: Full-Dimensional Quantum Dynamics

2021 ◽  
Author(s):  
Bin Zhao ◽  
Shanyu Han ◽  
Christopher Malbon ◽  
Uwe Manthe ◽  
David Yarkony ◽  
...  
Keyword(s):  
Quantum Dynamics ◽  
Branching Ratio ◽  
Nonadiabatic Dynamics ◽  
Energy Matrix ◽  
Elastic Channel ◽  
Potential Energy Matrix ◽  
Electronically Excited ◽  
Oppenheimer Approximation ◽  
Dynamical Method ◽  
Good Agreement

Abstract The breakdown of the Born-Oppenheimer approximation is omnipresent in chemistry, but our detailed understanding of the nonadiabatic dynamics is still incomplete. In the present work, nonadiabatic quenching of electronically excited OH(A2S+) molecules by H2 molecules is investigated by a full-dimensional quantum dynamical method using a high quality diabatic potential energy matrix. Good agreement with experiment is found for the OH(X2P) ro-vibrational and L-doublet distributions. Furthermore, the nonadiabatic dynamics is shown to be controlled by stereodynamics, namely the orientation of the two reactants. The uncovering of a major (in)elastic channel, neglected in all previous analyses, resolves a long-standing experiment-theory disagreement concerning the branching ratio of the two electronic quenching channels.

Ultrafast nonadiabatic dynamics probed by nitrogen K-edge absorption spectroscopy

2020 ◽  
Vol 22 (5) ◽  
pp. 2667-2676 ◽  
Author(s):  
T. Northey ◽  
J. Norell ◽  
A. E. A. Fouda ◽  
N. A. Besley ◽  
M. Odelius ◽  
...  
Keyword(s):  
Excited States ◽  
Quantum Dynamics ◽  
Degrees Of Freedom ◽  
Nonadiabatic Dynamics ◽  
Edge Structure ◽  
Strongly Coupled ◽  
X Ray ◽  
Electronically Excited ◽  
Dynamics Simulations ◽  
X Ray Absorption

Quantum dynamics simulations are used to simulate the ultrafast X-ray Absorption Near-Edge Structure (XANES) spectra of photoexcited pyrazine including two strongly coupled electronically excited states and four normal mode degrees of freedom.

scholarly journals Full-dimensional quantum stereodynamics of the non-adiabatic quenching of OH(A2Σ+) by H2

2021 ◽  
Author(s):  
Bin Zhao ◽  
Shanyu Han ◽  
Christopher L. Malbon ◽  
Uwe Manthe ◽  
David. R. Yarkony ◽  
...  
Keyword(s):  
Quantum Dynamics ◽  
Previous Analysis ◽  
Branching Ratio ◽  
Energy Matrix ◽  
Elastic Channel ◽  
Electronically Excited ◽  
Oppenheimer Approximation ◽  
Electronic Motion ◽  
Adiabatic Dynamics ◽  
Good Agreement

AbstractThe Born–Oppenheimer approximation, assuming separable nuclear and electronic motion, is widely adopted for characterizing chemical reactions in a single electronic state. However, the breakdown of the Born–Oppenheimer approximation is omnipresent in chemistry, and a detailed understanding of the non-adiabatic dynamics is still incomplete. Here we investigate the non-adiabatic quenching of electronically excited OH(A2Σ+) molecules by H2 molecules using full-dimensional quantum dynamics calculations for zero total nuclear angular momentum using a high-quality diabatic-potential-energy matrix. Good agreement with experimental observations is found for the OH(X2Π) ro-vibrational distribution, and the non-adiabatic dynamics are shown to be controlled by stereodynamics, namely the relative orientation of the two reactants. The uncovering of a major (in)elastic channel, neglected in a previous analysis but confirmed by a recent experiment, resolves a long-standing experiment–theory disagreement concerning the branching ratio of the two electronic quenching channels.

Reactions of carbamides in electronically excited states

1978 ◽  
Vol 21 (11) ◽  
pp. 1513-1514
Author(s):  
Yu. A. Tishchenko ◽  
L. V. Orlovskaya ◽  
V. I. Danilova
Keyword(s):  
Excited States ◽  
Electronically Excited States ◽  
Electronically Excited
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