Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 37 for “"Nonadiabatic."”.
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Electronic Spin Coupled Nonadiabatic Dynamics
… we can explore the coupled spin-nuclear nonadiabatic dynamics in real systems, which may be abundant in systems with spin-orbit coupling or external magnetic fields.
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SEMICLASSICAL MOLECULAR DYNAMICS OF ADIABATIC AND NONADIABATIC PROCESSES
… it is also explored the idea of including nonadiabatic effects to semiclassical vibrational spectroscopy by employing the Meyer-Miller-Stock-Thoss mapping. In Chapter 3 a simple study case regarding the formaldehyde molecule is used to dig deeper into a tedious question regarding what can …
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Electronic Structure Methods for the Investigation of Nonadiabatic Dynamics
A detailed understanding of the interface between nuclear dynamics and electronic structure is crucial for describing excited state dynamics in photoexcited systems, a key aspect of modelling the efficiency of photovoltaic devices, among other applications. There has been a proliferation of …
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Nonadiabatic control of a superconducting qubit via strong driving
Quantum computation offers the promise of speeding up many calculations that are intractable on classical computers, including but not limited to factoring and the simulation of quantum mechanical systems. Quantum computation is achieved by replacing the bits of a classical computer with quoits. …
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Nonadiabatic Dynamics of Cis-Trans Photoisomerization --- a First Principles Study
Cis-trans photoisomerization is a chemical reaction which converts light to mechanical energy on a molecular scale. Unique methods which provide an accurate theoretical description of these reactions are presented here. An implementation of the ab initio multiple spawning (AIMS) dynamics algorithm …
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Electron transfer in solution : nonadiabatic dynamics and applications to catalysis
… design principles. Afterwards, we study nonadiabatic electron transfer in solution. After benchmarking various resummations of a fourth-order perturbation theory expansion of a generalized master equation memory kernel for the spin-boson model, we apply our theoretical understanding to …
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Nonadiabatic electron transfer in the condensed phase, via semiclassical and Langevin equation approach
In this dissertation, we discuss two methods developed during my PhD study to simulate electron transfer systems. The first method, the semi-classical approximation, is derived from the stationary phase approximation to the path integral in the spin-coherent representation. The resulting equation …
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Predicting Kinetics of Spin-Dependent Reactions in an External Magnetic Field with Nonadiabatic Statistical Theory
… in a range of magnetic fields using the nonadiabatic statistical theory (NAST). The new computational methodology is applied to the spin-forbidden isomerization of the Ni(dpp)Cl₂ complex, revealing a notable increase in the rate constants under strong field conditions. We also discuss …
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DEVELOPMENT OF HIGH LEVEL AB INITIO METHODS TO DESCRIBE NONADIABATIC EVENTS AND APPLICATIONS TO THE EXCITED STATES OF SMALL BIOLOGICAL MOLECULES
The development of quantum mechanics has historically allowed researchers to theoretically explore the fundamental physical properties of atoms and molecules. Although quantum mechanics has been around for almost a century, its use was largely limited by the computational complexity it demanded. In …
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Molecular beam studies of excitation and electron transfer reactions
… These distributions were interpreted in terms of nonadiabatic interaction along different regions of the KBrNa molecular potential energy surfaces. These nonadiabatic interactions were also used to help explain the differing fine-structure state populations produced in the previous NaBr + K …
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Theoretical studies of proton-coupled electron transfer in interfacial and photochemical energy conversion processes
… isotope effects. Numerical models for the nonadiabatic cathodic rate constant of proton discharge on an electrode were employed to understand this phenomenon as differing contributions of vibronic states for a transferring proton and deuteron. In addition, computational and theoretical …
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Tddft Derivative Couplings And Other Topics In Quantum Chemistry
… reactions may be classified as adiabatic or nonadiabatic depending on whether the reaction takes place on the same adiabatic potential energy surface or not. From research over the last two decades, we now understand that many processes in nature turn out to be nonadiabatic { including charge …
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Ab-initio molecular dynamics studies of laser- and collision-induced processes in multielectron diatomics, organic molecules and fullerenes
… molecular dynamics method, the so-called nonadiabatic quantum molecular dynamics (NA-QMD), for various molecular systems with many electronic and nuclear degrees of freedom. Thereby, the nuclei will be treated classically and the electrons with time-dependent density functional theory …
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Ion Cyclotron Resonance Heating Induced Transport in Stellarators and Other Asymmetric Toroids
… model is used to superimpose resonance heated nonadiabatic changes in an ion's magnetic moment on a Coulomb scattering model that contains the Spitzer coefficients of drag, velocity diffusion, and pitch angle scattering (PAS). Ion drift orbit equations of motion are set in a magnetic flux …
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Quantum Nuclear Dynamics: Application to Spin-Forbidden Transitions and Lifetime of Vibrational States
… a new direct molecular dynamics method to study nonadiabatic dynamics of spin-forbidden reactions in which nonradiative transitions between the electronic states of different spin multiplicities occur due to the relativistic effect of spin-orbit coupling. In this molecular dynamics method based …
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Coupled quantum systems in inflationary cosmology.
… gets contributions from both the diagonal (nonadiabatic evolution of frequency eigenvalues) and nondiagonal (nonadiabatic evolution of frequency eigenstates) effects. An additional characteristic effect of coupled quantization is the rotation of light eigenstates to heavy ones, which do not …
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The Sachs-Wolfe effect
… of matter where the density perturbations are nonadiabatic. The second part shows the agreement between the formalisms of Sachs and Wolfe's pioneering paper and the recent work of George Ellis and Marco Bruni which presents the study of cosmological perturbations in a gauge invariant and …
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Aspects of charge recombination and charge transport in organic solar cells and light-emitting devices
… between CT states and excitons and (discuss the nonadiabatic transitions between these states.
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Ether Chemistry On Si(100) And Desorption Kinetics Of Corresponding Alkyls And Alkoxides
… that the hydrideelimination mechanism exhibits nonadiabatic behavior. The mechanism most consistentwith the experimental kinetics involves a spin-crossing due to the electronic excitation ofthe surface dimer accepting the eliminated hydride. The energetics for the initialelectronic excitation …
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Coupled electron and nuclear dynamics in model systems
… of this work was to investigate the influence of nonadiabatic coupling on the dynamical changes of electron and nuclear density. The properties of electron density have neither been discussed in the stationary case, nor for excited electronic states or for a coupled electronic and nuclear motion. …
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