Sökning: "Kohn-Sham theory"

Visar resultat 1 - 5 av 17 avhandlingar innehållade orden Kohn-Sham theory.

  1. 1. Foundation of Density Functionals in the Presence of Magnetic Field

    Författare :Andre Laestadius; Michael Benedicks; Trygve Helgaker; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Current density functional theory; Hohenberg-Kohn theorems; paramagnetic current density functionals; Kohn-Sham theory; Levy-Lieb functional; variational principle; N-representable; degeneracy; Mathematics; Matematik;

    Sammanfattning : This thesis contains four articles related to mathematical aspects of Density Functional Theory.In Paper A, the theoretical justification of density methods formulated with current densities is addressed. It is shown that the set of ground-states is determined by the ensemble-representable particle and paramagnetic current density. LÄS MER

  3. 2. Molecular Quadratic Response Properties with Inclusion of Relativity

    Författare :Johan Henriksson; Patrick Norman; Juha Vaara; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; relativistic quantum chemistry; molecular physics; clamping levels; four-component Hartree-Fock theory; Kohn-Sham density functional theory; response theory; nonlinear optics; second-harmonic generation; two-photon absorption; excited state properties; optical power limiting; Computational physics; Beräkningsfysik;

    Sammanfattning : This thesis concerns quadratic response properties and their application to properties in Jablonski diagrams such as resonant two-photon absorption and excited state absorption. Our main interest lies in optical power limiting applications, and in this context, molecules containing heavy metal atoms prove superior. LÄS MER

  4. 3. Electronic characterization of molecules with application to organic light emitting diodes

    Författare :Emil Jansson; Hans Ågren; Leif Eriksson; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; OLED; DFT; Marcus theory; Response theory; Theoretical chemistry; Teoretisk kemi;

    Sammanfattning : The presented thesis is devoted to the field of organic light emittingdiodes (OLEDs). Time-dependent Kohn-Sham density functional theory(TDDFT) is applied in order to eludicate optical properties such as fluorescence andphosphorescence for some of the most important materials. LÄS MER

  5. 4. Theoretical prediction of properties of atomistic systems : Density functional theory and machine learning

    Författare :Alexander Lindmaa; Rickard Armiento; Igor Abrikosov; Torbjörn Björkman; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : The prediction of ground state properties of atomistic systems is of vital importance in technological advances as well as in the physical sciences. Fundamentally, these predictions are based on a quantum-mechanical description of many-electron systems. LÄS MER

  7. 5. Relativistic theory of laser-induced magnetization dynamics

    Författare :Ritwik Mondal; Peter M. Oppeneer; Jan Rusz; Olle Eriksson; Paul-Antoine Hervieux; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Relativistic quantum electrodynamics; magneto-optics; spin-orbit coupling; ultrafast demagnetization; inverse Faraday effect; magnetic inertia; Gilbert damping; Fysik; Physics;

    Sammanfattning : Ultrafast dynamical processes in magnetic systems have become the subject of intense research during the last two decades, initiated by the pioneering discovery of femtosecond laser-induced demagnetization in nickel. In this thesis, we develop theory for fast and ultrafast magnetization dynamics. LÄS MER