Sökning: "First-Principles"
Visar resultat 6 - 10 av 281 avhandlingar innehållade ordet First-Principles.
6. Effects of disorder in metallic systems from First-Principles calculations
Sammanfattning : In this thesis, quantum-mechanical calculations within density-functional theory on metallic systems are presented. The overarching goal has been to investigate effects of disorder. In particular, one of the properties investigated is the bindingenergy shifts for core electrons in binary alloys using different theoretical methods. LÄS MER
7. Amorphous and crystalline functional materials from first principles
Sammanfattning : This thesis deals with various functional materials from first-principles methods and is divided into two major parts according to the underlying atomic structure of the system under study. The first part of the thesis deals with the temperature-induced structural phase transitions in metallic β'-AuZn and perovskite oxide LiOsO3. LÄS MER
8. First Principles Studies of Carbon Based Molecular Materials
Sammanfattning : The aim of this thesis was to investigate carbon based molecular materials at first principles levels. Special attention has been paid to simulations of X-ray spectroscopies, including near edge X-ray absorption fine structure (NEXAFS), X-ray photoelectron, and X-ray emission spectroscopy, which can provide detailed information about core, occupied and unoccupied molecular orbitals of the systems under investigation. LÄS MER
9. First principles simulations of electron transport at the molecule-solid interface
Sammanfattning : In this thesis I concentrate on the description of electron transport properties of microscopic objects, including molecular junctions and nano junctions, in particular, inelastic electron tunneling in surface-adsorbate systems are examined with more contemplations. Boosted by the rapid advance in experimental techniques at the microscopic scale, various electric experiments and measurements sprung up in the last decade. LÄS MER
10. Proton conductivity of lanthanum and barium zirconate: Microscale aspects on first-principles basis
Sammanfattning : Fuel cells are devices which convert chemical energy into electrical energy cleanly and efficiently. Development of fuel cells compatible with hydrocarbon fuels would make more efficient use of present fossil and renewable fuels, and also enable progress towards a future hydrogen economy. LÄS MER