Sökning: "cluster model calculations"

Visar resultat 1 - 5 av 57 avhandlingar innehållade orden cluster model calculations.

  1. 1. Case studies in omniparametric simulation

    Författare :Fredrik Lundin; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; growth model; Ising model; Markov chain; omnithermal simulation; omniparametric simulationpercolatiion; Potts model; parameter estimation; partial observations; random cluster model; Richardson model; simulation driven parameter estimation; two-type Richardson model; omnithermal simulation;

    Sammanfattning : In the eld of particle systems and growths models simulation is an important tool. When explicit calculations are too complex or impossible to perform we may use simulations instead. We adapt a new technique here denoted omniparametric simulation, to the two-type Richardson, Ising and Potts models. LÄS MER

  2. 2. A Treatise on the Geometric and Electronic Structure of Clusters : Investigated by Synchrotron Radiation Based Electron Spectroscopies

    Författare :Andreas Lindblad; Olle Björneholm; Gunnar Öhrwall; Maxim Tchaplyguine; Paolo Milani; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Cluster; nanoparticle; Heterogeneous; Homogeneous; Mixed; Cluster production methods; co-expansion; pick-up; doping; Cluster geometry; radial segregation; Interatomic Coulombic Decay; ICD; Auger electron spectroscopy; AES; X-ray photoelectron spectroscopy; XPS; Ultra-violet spectroscopy; UPS; Noble gas; Rare gas; Ne; Ar; Kr; Xe; Ammonia; NH3; Sulphur hexafluoride; SF6; MAX-lab; BESSY; Physics; Fysik;

    Sammanfattning : Clusters are finite ensembles of atoms or molecules with sizes in the nanometer regime (i.e. nanoparticles). This thesis present results on the geometric and electronic structure of homogeneous and heterogeneous combinations of atoms and molecules. LÄS MER

  3. 3. Combined Molecular Dynamics and Embedded-Cluster Calculations in Metal Oxide Surface Chemistry

    Författare :Björn Herschend; Kersti Hermansson; Micael Baudin; Joachim Sauer; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Inorganic chemistry; embedded-cluster; ab initio; molecular dynamics; metal oxide; ceria; magnesium oxide; adsorption; surface defect; Oorganisk kemi; Inorganic chemistry; Oorganisk kemi;

    Sammanfattning : The development and improvement of the functionality of metal oxides in heterogeneous catalysis and other surface chemical processes can greatly benefit from an atomic-level understanding of the surface chemistry. Atomistic calculations such as quantum mechanical (QM) calculations and molecular dynamics (MD) simulations can provide highly detailed information about the atomic and electronic structure, and constitute valuable complements to experimental surface science techniques. LÄS MER

  4. 4. Quantum Chemical Cluster Modeling of Enzymatic Reactions

    Författare :Rongzhen Liao; Fahmi Himo; Robert Deeth; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cluster approach; density functional theory; B3LYP; enzyme; mechanism; dinuclear; trinuclear; zinc; tungsten; hydrolysis; decarboxylation; formaldehyde oxidation; hydration; methyl transfer; Quantum chemistry; Kvantkemi; organisk kemi; Organic Chemistry;

    Sammanfattning : The Quantum chemical cluster approach has been shown to be quite powerful and efficient in the modeling of enzyme active sites and reaction mechanisms. In this thesis, the reaction mechanisms of several enzymes have been investigated using the hybrid density functional B3LYP. LÄS MER

  5. 5. Infrared and Photoelectron Spectroscopic Studies of Adsorbates on Solid Surfaces: Experiments and DFT Calculations

    Författare :Jakob Blomquist; Kemisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetic resonance; supraconductors; magnetic and optical properties; electrical; Solid Surfaces; Chemistry; Kemi; Condensed matter:electronic structure; FTIR spectroscopy; DFT Cluster calculations; Anharmonicity; Photoelectron spectroscopy; relaxation; spectroscopy; Kondenserade materiens egenskaper:elektronstruktur; egenskaper elektriska; magnetiska och optiska ; supraledare; magnetisk resonans; spektroskopi; Surface and boundary layery chemistry; Ytkemi; gränsskikt;

    Sammanfattning : In general, the more complex and real a system is, with all its interactions with solvents and contaminations etc., the harder it is to accurately model it and reproduce the experimental results by calculations. LÄS MER