Sökning: "Henrik Rydberg"

Hittade 5 avhandlingar innehållade orden Henrik Rydberg.

  1. 1. Correlation density functional beyond the atomic scale

    Författare :Henrik Rydberg; Chalmers University of Technology; []
    Nyckelord :;

    Sammanfattning : .... LÄS MER

  2. 2. Nonlocal Correlations in Density Functional Theory

    Författare :Henrik Rydberg; Chalmers University of Technology; []
    Nyckelord :bonding; GGA; adhesion; graphene; DFT; exchange; adsorption; LDA; first principles; polarization; vdW; determinants; correlation; graphite; surface states; van der Waals; density-functional theory; physisorption; nonlocal; functional;

    Sammanfattning : In Density Functional Theory, the widely used local and semilocal approximations to the exchange-correlation energy, the local density approximation (LDA) and the generalized gradient approximations (GGAs), lack a physical description of truly nonlocal correlation effects, which are absolutely essential for a proper description of soft matter. A scheme is proposed that provides a basis for systematic improvements beyond LDA and GGA, including correlations at intermediate and long range, giving rise to bonds of pure van der Waals type as well as more intricate, intermediate-range correlation bonds. LÄS MER

  3. 3. Integrated Communications and Thermal Management Systems for Microsystem-based Spacecraft : A Multifunctional Microsystem Approach

    Författare :Henrik Kratz; Anders Rydberg; Johan Köhler; Pelle Rangsten; Uppsala universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electronics; nanospacecraft; MST; MEMS; silicon; communication; thermal management; antenna; paraffin; PCM; multifunctional; microsystems; Elektronik; Electronics; Elektronik;

    Sammanfattning : This thesis explores the potential of multifunctional silicon-based microsystems for advanced integrated nanospacecraft (AIN). Especially, multifunctional microsystems with the coexistant functions of communications and thermal management implemented in multilayer silicon stacks are approached with systems study. LÄS MER

  4. 4. Quantal trajectories and geometric phase

    Författare :Henrik Carlsen; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Quantum chemistry; Kvantkemi; Quantum chemistry; Kvantkemi; Quantum Chemistry; kvantkemi;

    Sammanfattning : This thesis concerns the following topics: geometric phase in the context of Galilean invariance and quantum measurements, Rydberg states of hydrogen atoms, vibronic coupling in the E Ä e Jahn-Teller system and realism in quantum computations. In the analyses the de Broglie-Bohm pilot-wave formulation of quantummechanics is mainly used. LÄS MER

  5. 5. Chemical Bonding of Hydrocarbons to Metal Surfaces

    Författare :Henrik Öström; Anders Nilsson; Phil Woodruff; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Adsorption; hydrocarbon; core-level; spectroscopy; Physics; Fysik;

    Sammanfattning : Using x-ray absorption spectroscopy (XAS), x-ray emission spectroscopy (XES) and x-ray photoelectron spectroscopy (XPS) in combination with density functional theory (DFT) the changes in electronic and geometric structure of hydrocarbons upon adsorption are determined. The chemical bonding is analyzed and the results provide new insights in the mechanisms responsible for dehydrogenation in heterogeneous catalysis. LÄS MER