Understanding Processes Following Resonant Electron Attachment: Minimum-Energy Crossing Points between Anionic and Neutral Potential Energy Surfaces

2018 ◽  
Vol 14 (8) ◽  
pp. 4216-4223 ◽  
Author(s):  
Zsuzsanna Benda ◽  
Thomas-C. Jagau
Keyword(s):  
Potential Energy ◽  
Potential Energy Surfaces ◽  
Minimum Energy ◽  
Electron Attachment ◽  
Resonant Electron ◽  
Energy Surfaces

Calculations of the active mode and energetic barrier to electron attachment to CF3 and comparison with kinetic modeling of experimental results

2016 ◽  
Vol 18 (45) ◽  
pp. 31064-31071 ◽  
Author(s):  
Huixian Han ◽  
Benjamin Alday ◽  
Nicholas S. Shuman ◽  
Justin P. Wiens ◽  
Jürgen Troe ◽  
...  
Keyword(s):  
Neural Network ◽  
Potential Energy ◽  
Ab Initio ◽  
Kinetic Modeling ◽  
Potential Energy Surfaces ◽  
Electron Attachment ◽  
Invariant Polynomial ◽  
Active Mode ◽  
Polynomial Neural Network ◽  
Energy Surfaces

Six-dimensional potential energy surfaces of both CF3 and CF3− were developed by fitting ∼3000 ab initio points using the permutation invariant polynomial-neural network (PIP-NN) approach.

scholarly journals Nonadiabatic Dynamics in Multidimensional Complex Potential Energy Surfaces

2020 ◽  
Author(s):  
Fábris Kossoski ◽  
Mario Barbatti
Keyword(s):  
Potential Energy ◽  
Potential Energy Surfaces ◽  
Electron Attachment ◽  
Complex Surface ◽  
Nonadiabatic Dynamics ◽  
Surface Hopping ◽  
Molecular Systems ◽  
Out Of Plane ◽  
Dynamics Simulations ◽  
Energy Surfaces

<p>Despite the continuous development of theoretical methodologies for describing nonadiabatic dynamics of molecular systems, there is a lack of approaches for processes where the norm of the wave function is not conserved, i.e., when an imaginary potential accounts for some irreversible decaying mechanism. Current approaches rely on building potential energy surfaces of reduced dimensionality, which is not optimal for more involving and realistic multidimensional problems. Here, we present a novel methodology for describing the dynamics of complex-valued molecular Hamiltonians, which is a generalisation of the trajectory surface hopping method. As a first application, the complex surface fewest switches surface hopping (CS-FSSH) method was employed to survey the relaxation mechanisms of the shape resonant anions of iodoethene. We have provided the first detailed and dynamical picture of the p*/s* mechanism of dissociative electron attachment in halogenated unsaturated compounds, which is believed to underlie electron-induced reactions of several molecules of interest. Electron capture into the p* orbital promotes C=C stretching and out-of-plane vibrations, followed by charge transfer from the double bond into the s* orbital at the C-I bond, and, finally, release of the iodine ion, all within only 15 fs. On-the-fly dynamics simulations of a vast class of processes can be envisioned with the CS-FSSH methodology, including autoionisation from transient anions, core-ionised and superexcited states, Auger and interatomic Coulombic decay, and time-dependent luminescence.</p>

Partial Potential Energy Surfaces and Their Application to Reaction Resonances

2017 ◽  
Vol 42 (3) ◽  
pp. 300-305
Author(s):  
Ang-Yang Yu
Keyword(s):  
Potential Energy ◽  
Potential Energy Surfaces ◽  
Energy Surface ◽  
Minimum Energy ◽  
Reactive Systems ◽  
Resonance State ◽  
Minimum Energy Path ◽  
Feshbach Resonances ◽  
Energy Surfaces ◽  
Elementary Chemical

Feshbach resonances are not restricted to small reactive systems such as F + H2 and I + HI but can be found in many reactive systems. In this paper, the concept of the partial potential energy surface (PPES) is introduced. It is shown that the dynamic “Lake Eyring” explains very well the existence of reactive resonances in elementary chemical reactions. In particular, the PPESs of the Cl + CH3CH2Br and Cl + CH3CH2CH2Br systems, including the minimum energy path and the vibrational potential energy curves, were constructed using quantum chemistry methods. Based on the constructed PPESs, the scattering resonance states of these reactions could be examined and the resonance state lifetimes were estimated.

scholarly journals Nonadiabatic Dynamics in Multidimensional Complex Potential Energy Surfaces

2020 ◽  
Author(s):  
Fábris Kossoski ◽  
Mario Barbatti
Keyword(s):  
Potential Energy ◽  
Potential Energy Surfaces ◽  
Electron Attachment ◽  
Complex Surface ◽  
Nonadiabatic Dynamics ◽  
Surface Hopping ◽  
Molecular Systems ◽  
Out Of Plane ◽  
Dynamics Simulations ◽  
Energy Surfaces

<p>Despite the continuous development of theoretical methodologies for describing nonadiabatic dynamics of molecular systems, there is a lack of approaches for processes where the norm of the wave function is not conserved, i.e., when an imaginary potential accounts for some irreversible decaying mechanism. Current approaches rely on building potential energy surfaces of reduced dimensionality, which is not optimal for more involving and realistic multidimensional problems. Here, we present a novel methodology for describing the dynamics of complex-valued molecular Hamiltonians, which is a generalisation of the trajectory surface hopping method. As a first application, the complex surface fewest switches surface hopping (CS-FSSH) method was employed to survey the relaxation mechanisms of the shape resonant anions of iodoethene. We have provided the first detailed and dynamical picture of the π*/σ* mechanism of dissociative electron attachment in halogenated unsaturated compounds, which is believed to underlie electron-induced reactions of several molecules of interest. Electron capture into the π* orbital promotes C=C stretching and out-of-plane vibrations, followed by charge transfer from the double bond into the σ* orbital at the C-I bond, and, finally, release of the iodine ion, all within only 15 fs. On-the-fly dynamics simulations of a vast class of processes can be envisioned with the CS-FSSH methodology, including autoionisation from transient anions, core-ionised and superexcited states, Auger and interatomic Coulombic decay, and time-dependent luminescence.</p>

Potential Energy Surfaces

2018 ◽  
Author(s):  
Niels Engholm Henriksen ◽  
Flemming Yssing Hansen
Keyword(s):  
Schrödinger Equation ◽  
Potential Energy ◽  
Potential Energy Surfaces ◽  
Schrodinger Equation ◽  
Minimum Energy ◽  
Electronic Energy ◽  
Hydrogen Atoms ◽  
Approximate Analytical Solutions ◽  
London Equation ◽  
Energy Surfaces

This chapter discusses potential energy surfaces, that is, the electronic energy as a function of the internuclear coordinates as obtained from the electronic Schrödinger equation. It focuses on the general topology of such energy surfaces for unimolecular and bimolecular reactions. To that end, concepts like saddle point, barrier height, minimum-energy path, and early and late barriers are discussed. It concludes with a discussion of approximate analytical solutions to the electronic Schrödinger equation, in particular, the interaction of three hydrogen atoms expressed in terms of Coulomb and exchange integrals, as described by the so-called London equation. From this equation it is concluded that the total electronic energy is not equal to the sum of H–H pair energies. Finally, a semi-empirical extension of the London equation—the LEPS method—allows for a simple but somewhat crude construction of potential energy surfaces.

scholarly journals Nonadiabatic Dynamics in Multidimensional Complex Potential Energy Surfaces

2020 ◽  
Author(s):  
Fábris Kossoski ◽  
Mario Barbatti
Keyword(s):  
Potential Energy ◽  
Potential Energy Surfaces ◽  
Electron Attachment ◽  
Complex Surface ◽  
Nonadiabatic Dynamics ◽  
Surface Hopping ◽  
Molecular Systems ◽  
Out Of Plane ◽  
Dynamics Simulations ◽  
Energy Surfaces

<p>Despite the continuous development of theoretical methodologies for describing nonadiabatic dynamics of molecular systems, there is a lack of approaches for processes where the norm of the wave function is not conserved, i.e., when an imaginary potential accounts for some irreversible decaying mechanism. Current approaches rely on building potential energy surfaces of reduced dimensionality, which is not optimal for more involving and realistic multidimensional problems. Here, we present a novel methodology for describing the dynamics of complex-valued molecular Hamiltonians, which is a generalisation of the trajectory surface hopping method. As a first application, the complex surface fewest switches surface hopping (CS-FSSH) method was employed to survey the relaxation mechanisms of the shape resonant anions of iodoethene. We have provided the first detailed and dynamical picture of the π*/σ* mechanism of dissociative electron attachment in halogenated unsaturated compounds, which is believed to underlie electron-induced reactions of several molecules of interest. Electron capture into the π* orbital promotes C=C stretching and out-of-plane vibrations, followed by charge transfer from the double bond into the σ* orbital at the C-I bond, and, finally, release of the iodine ion, all within only 15 fs. On-the-fly dynamics simulations of a vast class of processes can be envisioned with the CS-FSSH methodology, including autoionisation from transient anions, core-ionised and superexcited states, Auger and interatomic Coulombic decay, and time-dependent luminescence.</p>

Probing the Potential Energy Surfaces of BrCN– by Dissociative Electron Attachment

2020 ◽  
Vol 11 (21) ◽  
pp. 9110-9116
Author(s):  
Xiao-Fei Gao ◽  
Feng An ◽  
Hao Li ◽  
Jing-Chen Xie ◽  
Xu-Dong Wang ◽  
...  
Keyword(s):  
Potential Energy ◽  
Potential Energy Surfaces ◽  
Electron Attachment ◽  
Dissociative Electron Attachment ◽  
Energy Surfaces
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