Search for dissertations about: "first-principles theory"

Showing result 6 - 10 of 175 swedish dissertations containing the words first-principles theory.

2. 6. First Principles Studies of Carbon Based Molecular Materials

   Author : Bin Gao; Yi Luo; Piero Decleva; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; first principles simulations; carbon based molecular materials; X-ray spectroscopies; Theoretical chemistry; Teoretisk kemi;

   Abstract : 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. READ MORE

4. 7. First-principles calculations of polymer interactions

   Author : Jesper Kleis; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; polymer structure; polyvinylchloride.; polypropylene; polyethylene; sparse material systems; Density functional theory; polymer interactions; van der Waals interaction; polymer crystal; soft matter; DFT;

   Abstract : This thesis reports on studies of interactions in sparse matter by first-principles calculations, in particular polymeric systems. The focus is on the three unbranched simple polymers: polyethylene (PE), isotactic polypropylene (PP) and isotactic polyvinylchloride (PVC), which together represent an important class of materials that form complexes stabilized by weak but long-range dispersive interactions. READ MORE

5. 8. First-Principles Studies of Materials Properties : Pressure-Induced Phase Transitions & Functional Materials

   Author : Thanayut Kaewmaraya; Rajeev Ahuja; Scheicher Ralph; Naurang Saini; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Density functional theory; Pressure-induced phase transitions; Ab-initio molecular dynamic; hybrid functional; Ab-initio random structure searching; Phase change material; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Abstract : This thesis presents the first-principles studies of materials properties within the framework of the density functional theory (DFT). The thesis constitutes three main parts, i. e., pressure-induced phase transitions in solids, data-storage and clean-energy materials. READ MORE

6. 9. High Resolution Tip-Enhanced Raman Images of Single Molecules from First Principles Simulations

   Author : Zhen Xie; Yi Luo; Filippo De Angelis; KTH; []
   Keywords : First Principles; Tip-Enhanced Raman Images; light-matter interactions at the nanoscale; Teoretisk kemi och biologi; Theoretical Chemistry and Biology;

   Abstract : With the precise control of spatially confined plasmon (SCP), tip-enhanced Raman spectroscopy (TERS) has achieved sub-nanometer resolution, leading to the chemical and physical characterization of the single molecule by optical Raman images. In the high resolution TERS measurements, the SCP spatial distribution generates the position-dependent Raman images. READ MORE

7. 10. Proton conductivity of lanthanum and barium zirconate: Microscale aspects on first-principles basis

   Author : Joakim Nyman; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; first principles; trapping; conductivity; grain boundary; segregation; pyrochlore; space charge; solid oxide fuel cell; depletion; electrolyte; La2Zr2O7; oxygen vacancy; BaZrO3; proton; DFT; point defect; perovskite; acceptor;

   Abstract : 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. READ MORE