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Showing 1 to 20 of 883 for “"Density-Functional Theory"”.
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Partition density functional theory
<p>Partition density functional theory (PDFT) is a method for dividing a molecular electronic structure calculation into fragment calculations. The molecular density and energy corresponding to Kohn Sham density-functional theory (KS-DFT) may be exactly recovered from these fragments. Each fragment …
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Density Functional Theory: Development and Applications
We describe the utility of Density Functional Theory (DFT) to explain phenomena of practical interest in Part I and embark upon further development of this powerful method in Part II. Specifically, we show that DFT can be used to predict enantioselectivities and regioselectivities (Chapters 3 and …
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Constrained Density-Functional Theory--Configuration Interaction
… electronic structure calculations, "Constrained Density Functional Theory-- Configuration Interaction" (CDFT-CI), which builds upon the computational strengths of Density Functional Theory and improves upon it by including higher level treatments of electronic correlation which are not readily …
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Orbital Polarization in Relativistic Density Functional Theory
… the ground state of the considered system. Density functional theory (DFT) methods apparently are the most widely spread self-consistent methods to investigate the ground state properties. This is due to their high computational efficiency and very good accuracy. In the framework of DFT, …
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Orbital Functionals in Time-Dependent Density-Functional Theory
The subject of this work are orbital functionals in density-functional theory (DFT). After a short introduction the basic ideas of static and time-dependent DFT are presented in Chap. 2. In this chapter the advantages and disadvantages of common approximations for the exchange-correlation (xc) …
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Density functional theory calculations on materials in photocatalysis
… friendly. In this thesis, we report density functional theory (DFT) calculations on several promising semiconductor materials used in photocatalytic water splitting aiming to achieve a better understanding on a theoretical level. In chapter 3, we report extensive DFT calculations on …
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Density-to-Potential Inversions in Density Functional Theory
Density functional theory and many of its extensions are formally exact quantum many-body theories. In practice, however, implementations of these theories use approximations for all but the most trivial systems. We present a set of inversion methods to numerically compute the exact potentials …
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Density functional theory investigations of graphene-based heterostructures
… electrodes. The present study employs Density Functional Theory (DFT) to identify the atomic and electronic structure of graphene (Gr) on three different types of substrates: transition metals (nickel, palladium), insulators (hBN) and semiconductors (MoS2). Our DFT calculations show …
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Calculating Magnetic Properties of Materials Using Density Functional Theory
… has been done for extending the van der Waals density functional to include spin-polarization effects, which is necessary for the computational study of weakly interacting systems where spin also plays an important role.
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Density-functional theory and beyond for organic electronic materials
… der Renormalized Second-order Perturbation Theory (rPT2). Der theoretische Zugang von rPT2 liegt in der Vielteilchenstörungstheorie und ist deshalb abhängig vom Startpunkt, also abhängig vom ungestörten Hamiltonoperator. Diese Arbeit zeigt durch umfangreiche Benchmark-Rechnungen, dass die …
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Orbital-free density functional theory using higher-order finite differences
Density functional theory (DFT) is not only an accurate but also a widely used theory for describing the quantum-mechanical electronic structure of matter. In this approach, the intractable problem of interacting electrons is simplified to a tractable problem of non-interacting electrons moving in …
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Density-functional Theory Applied To Problems In Catalysis And Electrochemistry
… surfaces below one monolayer coverage using density-functional theory. The results of this study provide a theoretical framework for interpreting recent experimental results on the redox properties of water at ceria (111) surfaces. In particular, we have computed the structure and energetics …
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Density Functional Theory Study of Two-Dimensional Boron Nitride Films
… or multilayer form. In my thesis work, I used density functional theory (DFT) calculations to investigate the properties of boron nitride films. In particular, I first studied the properties (i.e. formation energy, defect states, and structure) of point charged defects in monolayer and bilayer …
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Density Functional Theory Study of Aromatic Adsorption on Iron Surfaces
… of aromatic molecules on iron surfaces using density functional theory (DFT) calculations. The adsorbates studied are benzene ($C_{6}H_{6}$), naphthalene ($C_{8}H_{10}$) and quinolinium ($C_{7}H_{10}N^{+}$) as well as a molecule composed of these fragments known to inhibit acid corrosion on …
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Taming the Inverse and Forward Problems in Density Functional Theory
The `forward problem' of ground-state density functional theory (DFT) constitutes finding the ground-state density $n(x)$ that minimises a Kohn-Sham total energy functional defined using some exchange-correlation (xc) functional $E_\text{xc}[n]$. Towards this end, the associated Euler-Lagrange …
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Understanding and Improving Hydrogen Storage Materials with Density Functional Theory Methods
… materials can be modeled computationally with density functional theory, and I describe some of the myriad assumptions and methods necessary to do that.
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Correlated electron dynamics and memory in time-dependent density functional theory
Korrelierte Elektronendynamik ist für nichtlineare und lineare Prozesse in Atomen und Molekülen von großer Bedeutung. Dies betrifft insbesondere die Wechselwirkung mit starken Feldern und die Photoabsorptionsspektren. Die theoretische Beschreibung der Korrelationen gestaltet sich jedoch im …
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Charge and excitation-energy transfer in time-dependent density functional theory
… is of practical relevance. In principle, density functional theory (DFT) and time-dependent density functional theory (TDDFT) appear as natural choices to study the relevant sizable molecules on a first-principles scale at bearable computational cost. However, the application of standard …
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