Assessment of Reactivity Descriptors for the Study of Chemical Reactions
type: CreativeWork
description: At present, a plethora of techniques is available to study molecular systems and chemical reactions. In this light, ab initio many body techniques enable us, without any experimental input, to compute molecular energetics and a whole range of chemical properties. A twofold classification can be made, separating wave function based methods (such as Hartree-Fock) from density functional theory (DFT). In this thesis, the focus mainly lies on the density functional method, both from a conceptual as computational viewpoint - for the latter, one of the reasons being its excellent cost-to-performance ratio. The formulation of the Hohenberg-Kohn theorems in 1964 provided the starting point for the fast development of fundamental DFT, yielding all basic ingredients for a complete many-body theory. In a next step, Kohn and Sham introduced orbitals within the formalism, paving the way to a breakthrough of DFT as an important computational tool within modern chemistry. In addition to these developments, much attention has been paid to the insights DFT can give into chemical reactivity. In particular, the density functional methodology provides an excellent framework to define a variety of well-known chemical concepts. In this thesis, the applicability of several fundamental DFT-based reactivity indicators has been tested for a variety of reactions occurring in diverse domains of chemistry. The chemical potential, global hardness and global softness are used to discuss the reactive behavior of one single molecule or a set of related molecules, providing reactivity sequences for the latter. The Fukui function is used as an intra-molecular descriptor, whereas the local softness can provide inter-molecular reactivity information about regio selectivity. In order to test the usefulness of the aforementioned properties, they are usually used in conjunction with well-known chemical principles such as the electronegativity equalization, the principle of maximum hardness and the hard an…
abstract: At present, a plethora of techniques is available to study molecular systems and chemical reactions. In this light, ab initio many body techniques enable us, without any experimental input, to compute molecular energetics and a whole range of chemical properties. A twofold classification can be made, separating wave function based methods (such as Hartree-Fock) from density functional theory (DFT). In this thesis, the focus mainly lies on the density functional method, both from a conceptual as computational viewpoint - for the latter, one of the reasons being its excellent cost-to-performance ratio. The formulation of the Hohenberg-Kohn theorems in 1964 provided the starting point for the fast development of fundamental DFT, yielding all basic ingredients for a complete many-body theory. In a next step, Kohn and Sham introduced orbitals within the formalism, paving the way to a breakthrough of DFT as an important computational tool within modern chemistry. In addition to these developments, much attention has been paid to the insights DFT can give into chemical reactivity. In particular, the density functional methodology provides an excellent framework to define a variety of well-known chemical concepts. In this thesis, the applicability of several fundamental DFT-based reactivity indicators has been tested for a variety of reactions occurring in diverse domains of chemistry. The chemical potential, global hardness and global softness are used to discuss the reactive behavior of one single molecule or a set of related molecules, providing reactivity sequences for the latter. The Fukui function is used as an intra-molecular descriptor, whereas the local softness can provide inter-molecular reactivity information about regio selectivity. In order to test the usefulness of the aforementioned properties, they are usually used in conjunction with well-known chemical principles such as the electronegativity equalization, the principle of maximum hardness and the hard an…
author: Hemelsoet, Karen
language: eng
keywords: Chemistry, molecular modeling, chemical reactivity
date published: 2007
date modified: 2026-07-24T02:23:05Z
provider: Ghent University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Ghent University

PropertyValue
property ID: Handle
value: http://hdl.handle.net/1854/LU-516364