Sökning: "LCAO"

Hittade 5 avhandlingar innehållade ordet LCAO.

  1. 1. Studies of the electronic structure of some clean and As-covered semiconductor surfaces using angle- resolved photoelectron spectroscopy

    Författare :Hua Qu; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; crystal structure; LCAO; Surface electronic structure; diamond; LEED; zinc-blende;

    Sammanfattning : .... LÄS MER

  3. 2. Studies on Lean NOx Reduction with Ammonia. Catalysts and Sensors

    Författare :Mikaela Wallin; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; catalysis; Pt SiO2; NOx reduction; gas sensor; DFT; SCR; H-ZSM-5; in situ FTIR; LCAO; DRIFT; high throughput screening; transient ammonia supply; ammonia; microemulsion; perovskite;

    Sammanfattning : Selective catalytic reduction of NOx with ammonia, NH3-SCR, is a promising technique to reduce NOx under lean conditions, e.g. in diesel engine exhausts. The main objective of this thesis was to gain further understanding of key parameters affecting the performance of catalysts and sensors for NH3-SCR. LÄS MER

  4. 3. Reduction of finite-group representations and influence of lattice symmetry on some properties in condensed-matter physics

    Författare :Per-Olof Jansson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The first part of this thesis describes a method for calculating irreducible matrix representatives of arbitrary finite groups. Using a projection operator technique, a problem of degeneracy in the eigenvalues appear. By using a linear combination of irreducible group representatives the degeneracy is shown to be removed. LÄS MER

  5. 4. Application of core level spectroscopy to adsorbate and coadsorbate systems

    Författare :Jörgen Hasselström; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik; Physics; Fysik; fysik; Physics;

    Sammanfattning : Different core level spectroscopies combined with quantum chemistry calculations have been applied to a number of adsorbate system. The objective has been to investigate the modification of the valence electronic structure of the adsorbates due to the chemical bond formed with the substrate atoms. LÄS MER

  7. 5. Calculations of Linear and Nonlinear Optical Properties of Ionic Crystal Surfaces and Fullerenes

    Författare :Erik Westin; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Electronic and optical properties of ionic crystal surfaces and fullerenes have been studied by means of cluster calculations based on the Local Density Approximation (LDA) method using a numerical LCAO approach. The calculations for the bulk, stoichiometric and non-stoichiometric (111) surfaces of the divalent ionic crystals, CaF2 and BaF2, were based on the construction of an appropriate cluster of Ba++/Ca++ and F- ions representing a local environment of the specific system. LÄS MER