Search for dissertations about: "first-principles theory"
Showing result 16 - 20 of 175 swedish dissertations containing the words first-principles theory.
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16. First principles calculations of perovskites structural properties
Abstract : .... READ MORE
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17. Nonlocal Correlations in Density Functional Theory
Abstract : In Density Functional Theory, the widely used local and semilocal approximations to the exchange-correlation energy, the local density approximation (LDA) and the generalized gradient approximations (GGAs), lack a physical description of truly nonlocal correlation effects, which are absolutely essential for a proper description of soft matter. A scheme is proposed that provides a basis for systematic improvements beyond LDA and GGA, including correlations at intermediate and long range, giving rise to bonds of pure van der Waals type as well as more intricate, intermediate-range correlation bonds. READ MORE
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18. Structure and spectroscopy of bio- and nano-materials from first-principles simulations
Abstract : This thesis is devoted to first-principles simulations of bio- and nano-materials,focusing on various soft x-ray spectra, ground-state energies and structures of isolated largemolecules, bulk materials, and small molecules in ambient solutions. K-edge near-edge x-ray absorption fine structure (NEXAFS) spectra, x-ray emission spectra, andresonant inelastic x-ray scattering spectra of DNA duplexes have been studied by means oftheoretical calculations at the density functional theory level. READ MORE
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19. Thermal properties of materials from first principles
Abstract : In the search of clean and efficient energy sources intermediate temperature solid oxide fuel cells are among the prime candidates. What sets the limit of their efficiency is the solid electrolyte. A promising material for the electrolyte is ceria. READ MORE
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20. Magnetization dynamics on the nanoscale : From first principles to atomistic spin dynamics
Abstract : In this thesis first-principles methods, based on density functional theory, have been used to characterize a wide range of magnetic materials. Special emphasis has been put on pairwise magnetic interactions, such as Heisenberg exchange and Dzyaloshinskii-Moriya interactions, and also on in the Gilbert damping parameter. READ MORE