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Showing 1 to 20 of 957 for “"density functional"”.
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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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Towards Systematic Improvement of Density Functional Approximations
<p>Density functional theory is a formally exact theory to describe ground state properties due to the existence of the exact functional. In practice, the usefulness of density functional theory relies on the accuracy of density functional approximations. After decades of effort of functional …
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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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Density Functional Study of Hydrogen in Amorphous Silicon
Our calculations clarify the role of H during electronic defect formation. We calculate the energetics for H to move from a variety of Si-H bonds to the bulk chemical potential. For isolated Si-H bonds (i.e. in micro-cavities without any bond reconstruction) the energetics are not consistent with …
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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
Organische Elektronik ist ein agiles industrielles und auch akademisches Forschungsgebiet, das sich zum Ziel gesetzt hat, einfach zu erzeugende, kostengünstige sowie biegbare (opto-)elektronische Bauteile zu entwickeln. Allerdings öffnet die Anwendung der Dichtefunktionaltheorie (DFT) mit …
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Real time density functional simulations of quantum scale conductance
… state in real time using time-dependent density functional theory (TDDFT). This is in contrast with the more common steady-state nonequilibrium Green's function (NEGF) method. We start by examining quantum scale conductance methods in both the steady state and real-time formulations …
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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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Wannier Functions and Their Role in Improving Density Functional Approximations
<p>Density functional theory has proven to be an invaluable tool for modeling matter and chemistry . This can be seen from the fact that density functional theory papers are far and away the most cited theory from the physical sciences. While density functional theory excels at predicting total …
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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 Study of NO Decomposition With Cu-Exchanged Zeolites
… using a first-principles quantum mechanics-based density functional method. A small cluster model is proposed and used to examine the properties of zeolite-bound Cu ions, and their interactions with various species relevant to the decomposition process. Vibrational frequencies of the adsorbed …
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