Sökning: "Hans Ågren"
Visar resultat 11 - 15 av 46 avhandlingar innehållade orden Hans Ågren.
11. Quantum Chemical Studies of Mechanisms and Stereoselectivities of Organocatalytic Reactions
Sammanfattning : As the field of organocatalysis is growing, it is becoming more important to understand the specific modes of action of these new organic catalysts. Quantum chemistry, in particular density functional theory, has proven very powerful in exploring reaction mechanisms as well as selectivities in organocatalytic reactions, and is the tool used in this thesis. LÄS MER
12. Atomic decomposition of molecular properties
Sammanfattning : In this thesis, new methodology of computing properties aimed for multipleapplications is developed. We use quantum mechanics to compute propertiesof molecules, and having these properties as a basis, we set up equations basedon a classical reasoning. LÄS MER
13. Quantum chemical studies of epoxide-transforming enzymes
Sammanfattning : Density functional theory is employed to study the reaction mechanisms of different epoxide-transforming enzymes. Calculations are based on quantum chemical active site models, which are build from X-ray crystal structures. The models are used to study conversion of various epoxides into their corresponding diols or substituted alcohols. LÄS MER
14. Strategies for Performance Improvement of Quantum Dot Sensitized Solar Cells
Sammanfattning : Quantum dot sensitized solar cells (QDSCs) constitute one of the most promising low-cost solutions that are explored for the world’s needs of clean and renewable energy. Efficient, low-toxic and stable QDSCs for large-scale applications have formed the subject for the solar cell research during recent years. LÄS MER
15. Multimode resonant X-ray scattering of free molecules
Sammanfattning : This thesis is focused on the role that nuclear dynamics plays in the formation of X-ray absorption (XAS) and resonant inelastic X-ray scattering (RIXS) spectra of multimode free molecules. A combined approach based on ab initio electronic structure methods and quantum nuclear wave packet dynamics is applied to two systems -- water and methanol in the gas phase. LÄS MER