Search for dissertations about: "relativistic DFT"

Showing result 1 - 5 of 10 swedish dissertations containing the words relativistic DFT.

  1. 1. Quantum and quantum-classical calculations of core-ionized molecules in varied environments

    Author : Tuomas Löytynoja; Hans Ågren; Jukka Tulkki; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Electron spectroscopy; UPS; XPS; photodissociation; binding energy; ionization potential; computational; electronic structure; self-consistent field; DFT; QM MM; gas phase; liquid; solution; physisorption; metallic surface; polymer; charge transfer; Teoretisk kemi och biologi; Theoretical Chemistry and Biology;

    Abstract : Computational quantum chemistry methods have been applied in two particular cases: to provide insight to photoionization induced fragmentation of HgBr2 and HgCl2 molecules, and to study core-electron binding energies and chemical shifts of molecules in liquid, surface adsorbed and polymeric environments in the framework of quantum mechanics/molecular mechanics (QM/MM). In the photodissociation studies the computational work is based on the relativistic Dirac equation as the systems present strong spin-orbit interaction affecting the fragmentation processes. READ MORE

  2. 2. Theoretical Investigations of Selected Heavy Elements and Metal-hydrogen Systems by Means of Electronic Structure Calculations

    Author : Per Andersson; Manuel RichterI; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physics; actinides; metal-hydrogen systems; DFT; band structure; non-commensurate magnetism; Fysik; Physics; Fysik; fysik; Physics;

    Abstract : Using ab initio electronic structure calculations based on density functional theory the crystal, electronic and magnetic structures of selected materials have been investigated. The materials which are the subjects of these investigations can be divided into two groups. READ MORE

  3. 3. First-principles theory of electrically-induced spin and orbital magnetization

    Author : Leandro Salemi; Peter M. Oppeneer; Yuriy Mokrousov; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Spin-orbit torque; spin Hall effect; Rashba-Edelstein effect; spin Nernst effect; relativistic DFT; spin-orbitronics;

    Abstract : Spin-orbit torques (SOTs) have emerged recently as practical tools to control the magnetization in spintronic devices, but it is debated what the underlying fundamental processes are that enable fast and energy-efficient magnetization switching.In this thesis, we investigate theoretically possible means of controlling magnetization in magnetic materials and heterostructures. READ MORE

  4. 4. Atomistic spin dynamics and relativistic effects in chiral nanomagnets

    Author : Konstantinos Koumpouras; Anders Bergman; Olle Eriksson; Manuel Pereiro; Elena Vedmenenko; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : In this thesis, studies based on magnetization dynamics on atomic length scales are presented for a number of magnetic systems, where Dzyaloshinskii-Moriya (DM) interaction is present. First-principle methods, based on density functional theory (DFT), have been used to study the pairwise magnetic interactions, such as Heisenberg exchange and DM interaction, which are the crucial parameters for the helimagnetic systems. READ MORE

  5. 5. Theoretical calculations of heavy atom effects in magnetic resonance spectroscopy

    Author : Corneliu I. Oprea; Hans Ågren; Patrik Norman; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; nuclear spin-spin coupling tensor; nuclear shielding tensor; heavy atom effect; hyperfine coupling tensor; restricted-unrestricted approach; Theoretical chemistry; Teoretisk kemi;

    Abstract : This thesis presents quantum chemical calculations, applications of the response function formalism recently implemented within the framework of density functional theory (DFT) by our research group. The purpose of the calculations is to assess the performance of this perturbative approach to determining heavy atom effects on magnetic resonance parameters. READ MORE