Sökning: "first principles"
Visar resultat 6 - 10 av 880 avhandlingar innehållade orden first principles.
6. Materials Design from First Principles : stability and magnetism of nanolaminates
Sammanfattning : In this thesis, first-principles calculations within density functional theory are presented, with a principal goal to investigate the phase stability of so called Mn+1AXn (MAX) phases. MAX phases are a group of nanolaminated materials comprised of a transition metal (M), a group 12-16 element (A), and carbon or nitrogen (X). LÄS MER
7. 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
8. 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
9. 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
10. 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