Sökning: "Reverse Monte-Carlo"

Visar resultat 1 - 5 av 21 avhandlingar innehållade orden Reverse Monte-Carlo.

  1. 1. Structure Modeling with X-ray Absorption and Reverse Monte Carlo: Applications to Water

    Författare :Mikael Leetmaa; Lars G M Pettersson; John Rehr; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; water structure; x-ray absorption; spectroscopy; diffraction; reverse monte carlo; XAS; EXAFS; XANES; RMC; TP-DFT spectrum calculations; Physics; Fysik; kemisk fysik; Chemical Physics;

    Sammanfattning : Water is an important substance. It is part of us, of our environment, and is a fundamental prerequisite for the existence of life as we know it. The structure of water is still, after over 100 years of research on the subject, however under debate. LÄS MER

  2. 2. Neutron scattering and reverse Monte Carlo simulation studies of a polymer electrolyte, PPO-LiClO4

    Författare :Patrik Carlsson; Chalmers University of Technology; []
    Nyckelord :PPO-LiClO4; poly propylene oxide ; neutron diffraction; quasi-elastic neutron scattering; reverse Monte Carlo simulation; polymer electrolytes;

    Sammanfattning : .... LÄS MER

  3. 3. Beyond average crystal structures: understanding extended and local environments in proton-conducting Sc-substituted BaTiO3 perovskites

    Författare :Nico Torino; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES; proton conducting oxide; IR; thermogravimetry; perovskite; neutron scattering; Raman; Reverse Monte Carlo; ordering; BaTiO3;

    Sammanfattning : Proton conducting ceramics are very promising for applications concerned with energy sourcing with cleaner, safer, more abundant and cheaper alternatives to fossil fuels. These materials are still in development and advances in the field depend on a better understanding of the role of defects, their identification and location in the host framework, and the assessment of their short- and long-range dynamics and kinetics. LÄS MER

  4. 4. Atomic short-range order, optical and electronic properties of amorphous transition metal oxides : An experimental and theoretical study of amorphous titanium aTiO2 and tungsten aWO3 solid thin-film oxides

    Författare :Carlos A Triana; Tomas Edvinsson; Petter Persson; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; X-ray-Absorption; Reverse Monte Carlo; Molecular dynamics; Electronic structure;

    Sammanfattning : Amorphous transition metal oxides [aTMOs], have emerged as innovative functional materials for wide-ranging electronic, optical and energy-related applications. However, no systematic and broadly applicable method exists to assess their atomic-scale correlations, and since the optical and electronic processes are local structure-dependent, still there are not well-stablished mechanisms that suitably explain the physical properties of aTMOs. LÄS MER

  5. 5. Simulation of Core-Level Spectra of H-bonded Systems

    Författare :Iurii Zhovtobriukh; Lars G.M. Pettersson; Anders Nilsson; Marcus Lundberg; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; water; x-ray absorption; non-resonant x-ray emission; damped linear response theory; time-dependent density functional theory; semi-classical approximation to Kramers-Heisenberg formula; Reverse Monte-Carlo; kemisk fysik; Chemical Physics;

    Sammanfattning : The thesis consists of three related projects where attempts have been made to simulate X-Ray Absorption (XAS) spectra of water and hexagonal ice, static non-resonant X-ray Emission (XES) spectrum of water and to apply the semi-classical approximation to Kramers-Heisenberg formula (SCKH) formalism to calculate the non-resonant XES spectrum of water and methanol. The first project is devoted to an investigation of the performance of damped response theory in combination with the DFT electronic structure method (CPP-DFT) in XAS spectrum simulations of liquid water. LÄS MER