Sökning: "Beräkningsfysik"

Visar resultat 1 - 5 av 28 avhandlingar innehållade ordet Beräkningsfysik.

  1. 1. Time-dependent molecular properties in the optical and x-ray regions

    Författare :Ulf Ekström; Patrick Norman; Knut Faegri; Linköpings universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Quantum chemistry; molecular physics; x-ray spectroscopy; relativity; Computational physics; Beräkningsfysik;

    Sammanfattning : Time-dependent molecular properties are important for the experimental characterization of molecular materials. We show how these properties can be calculated, for optical and x-ray frequencies, using novel quantum chemical methods. LÄS MER

  2. 2. Light Control using Organometallic Chromophores

    Författare :Johan Henriksson; Patrick Norman; Olav Vahtras; Linköpings universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; organometallic chromophores; two-photon absorption; excited state absorption; excited state dipole moment; four-component formalism; clamping levels; spin-transition; Computational physics; Beräkningsfysik;

    Sammanfattning : The interaction between light and organometallic chromophores has been investigated theoretically in a strive for fast optical filters. The main emphasis is on two-photon absorption and excited state absorption as illustrated in the Jablonski diagram. We stress the need for relativistic calculations and have developed methods to address this issue. LÄS MER

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

    Författare :Johan Henriksson; Patrick Norman; Juha Vaara; Linköpings universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; 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. 4. Electron-lattice dynamics in π-conjugated systems

    Författare :Magnus Hultell (Andersson); Sven Stafström; Alessandro Troisi; Linköpings universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; charge transport; electron-lattice dynamics; polaron; adiabatic transport; electron localization; internal conversion; Computational physics; Beräkningsfysik;

    Sammanfattning : The work presented in this thesis concerns the dynamics in π-conjugated hydrocarbon systems. Due to the molecular bonding structure of these systems there exists a coupling between the electronic system and the phonons of the lattice. LÄS MER

  5. 5. Molecular Electronics : A Theoretical Study of Electronic Structure of Bulk and Interfaces

    Författare :Mikael Unge; Sven Stafström; Mads Brandbyge; Linköpings universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; molecular electronics; electron transport; disorder; localization; long-range correlation; organometallic magnets; interface dipole; Computational physics; Beräkningsfysik;

    Sammanfattning : This thesis deals with theoretical studies of the electronic structure of molecules used in the context of molecular electronics. Both studies with model Hamiltonians and first principle calculations have been performed. LÄS MER