Sökning: "TRANSITION-STATE THEORY"

Visar resultat 1 - 5 av 35 avhandlingar innehållade orden TRANSITION-STATE THEORY.

  1. 1. Theory of Hydrogen Quantum Diffusion

    Författare :Thomas Mattsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; path-integrals; isotope effect; transition state theory; quantum; diffusion; hydrogen; first-principles calculations; nickel;

    Sammanfattning : Atomic hydrogen adsorbed on a metal surface is one of the simplest possible examples of chemisorption, yet it is very challenging. The adsorption and the very elementary process of surface diffusion, a single atomic jump, have been investigated theoretically using several methods. LÄS MER

  3. 2. Modelling of molybdopterin-dependent enzymes

    Författare :Anders Thapper; Kemiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Inorganic chemistry; enzymes; transition state; intermediate; mechanism; molybdopterin; density functional theory; model systems; oxygen atom transfer; molybdenum; tungsten; Oorganisk kemi; Chemistry; Kemi;

    Sammanfattning : The thesis deals with models for molybdopterin-dependent enzymes. Several model systems containing molybdenum or tungsten have been prepared and characterised, and their reactivity with oxygen atom acceptors and donors have been investigated. LÄS MER

  4. 3. Influence of Global Composition and Local Environment on the Spectroscopic and Magnetic Properties of Metallic Alloys

    Författare :Weine Olovsson; Igor A. Abrikosov; G. Malcolm Stocks; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; core level shift; random alloy; first principles simulations; density functional theory; auger kinetic energy; Invar alloys; exchange parameter; classical Heisenberg Hamiltonian; complete screening; transition state; disorder broadening; Fysik; Physics; Fysik;

    Sammanfattning : Theoretical investigations of spectroscopic and magnetic properties of metallic systems in the bulk, as well as in nanostructured materials, have been performed within the density functional theory. The major part of the present work studies the differences between binding energies of electrons tightly bound to the atoms, the so-called core electrons (in contrast with the valence electrons), that is, core-level binding energy shift (CLS). LÄS MER

  5. 4. Computer Simulations in Materials Physics: Time-scales and Accuracy

    Författare :Urban Engberg; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; basis sets; computer simulations; pseudopotentials; materials physics; density functional theory; transition state theory; O N ; quantum Monte Carlo;

    Sammanfattning : Computer simulations are expected to play an increasingly important role within materials physics in the future. Owing to a combination of accurate physical approximations, improved implementations of these approximations, and the exponentially increasing power of computers, problems can now be solved on length and time-scales which were unimaginable only a decade ago. LÄS MER

  7. 5. Transition state theory from path-integrals, application to hydrogen diffusion on Ni(100)

    Författare :Thomas R. Mattson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; polaron; hydrogen; quantum; diffusion; monte carlo; path-integrals;

    Sammanfattning : .... LÄS MER