Sökning: "DFTB"

Hittade 4 avhandlingar innehållade ordet DFTB.

  1. 1. Linear models for multiscale materials simulations : Towards a seamless linking of electronic and atomistic models for complex metal oxides

    Författare :Akshay Krishna Ammothum Kandy; Peter Broqvist; Jolla Kullgren; Eddie Wadbro; Ben Hourahine; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Force fields; Electronic structure calculations; CCS; DFTB; CCS Q; repulsive fitting; Kemi med inriktning mot materialkemi; Chemistry with specialization in Materials Chemistry;

    Sammanfattning : Multiscale modelling approaches, connecting data from electronic structure calculations all the way towards engineering continuum models, have become an important ingredient in modern materials science. Materials modelling in a broader sense is already amply used to address complex chemical problems in academic science, but also in many industrial sectors. LÄS MER

  2. 2. Modelling of Molecular-Scale Nanoelectromechanical Systems

    Författare :Caroline Huldt; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; shuttle; mesoscopic; NEMS; graphene; multiscale; DFTB; DFT;

    Sammanfattning : Nanoelectromechanical systems (NEMS) couple electronic and mechanical degrees of freedom in a nanoscopic structure. The small size introduces many atomistic and quantum mechanical features which on the one hand open up for interesting new features and possibilities but on the other hand make it very difficult to formulate quantitative predictions. LÄS MER

  3. 3. Chemistry and Physics of Cu and H2O on ZnO Surfaces : Electron Transfer, Surface Triangles, and Theory

    Författare :Matti Hellström; Kersti Hermansson; Peter Broqvist; Daniel Spångbeg; Jörg Behler; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; catalysis; density functional theory; SCC-DFTB; band-filling correction;

    Sammanfattning : This thesis discusses the chemistry and physics of Cu and H2O on ZnO surfaces, based primarily on results from quantum chemical calculations. The underlying context is heterogeneous catalysis, where Cu/ZnO-mixtures are used in the industrial synthesis of methanol and in the water gas shift reaction. LÄS MER

  4. 4. Ghost in the shell : Studies on subsurface oxygen in oxide-derived copper nanocube catalysts

    Författare :Liu Chang; Lars Pettersson; Anders Nilsson; Tore Brinck; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; teoretisk fysik; Theoretical Physics;

    Sammanfattning : With the passage of time and the advancement of our industrial civilization, environmental concerns have become more and more recognized since the 1990s. Carbon dioxide reduction reactions are capable of converting carbon dioxide into valuable hydrocarbons and reducing the carbon emission from the combustion of fossil fuels. LÄS MER