Search for dissertations about: "NATURAL SCIENCES Chemistry Theoretical chemistry Quantum chemistry"

Showing result 11 - 15 of 189 swedish dissertations containing the words NATURAL SCIENCES Chemistry Theoretical chemistry Quantum chemistry.

  1. 11. Quantum dynamical effects in complex chemical systems

    Author : S. Karl-Mikael Svensson; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Quantum dynamics; Radiative association; Classical Wigner method; Feynman path integral; Reaction rate constants; Wigner phase space;

    Abstract : When using mathematical models to computationally investigate a chemical system it is important that the methods used are accurate enough to account for the relevant properties of the system and at the same time simple enough to be computationally affordable. This thesis presents research that so far has resulted in three published papers and one unpublished manuscript. READ MORE

  2. 12. Photoluminescence Characteristics of III-Nitride Quantum Dots and Films

    Author : Martin Eriksson; Per-Olof Holtz; Peder Bergman; Fredrik Karlsson; Volodymyr Khranovskyy; Yasuhiko Arakawa; Linköpings universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : III-Nitride semiconductors are very promising in both electronics and optical devices. The ability of the III-Nitride semiconductors as light emitters to span the electromagnetic spectrum from deep ultraviolet light, through the entire visible region, and into the infrared part of the spectrum, is a very important feature, making this material very important in the field of light emitting devices. READ MORE

  3. 13. Theoretical studies of porphyrin proteins

    Author : Emma Sigfridsson; Beräkningskemi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; molecular mechanics; quantum chemical calculations; electrostatic potential charges; atomic charges; ferrochelatase; cytochrome; myoglobin; Porphyrin; haem; QM MM; reorganisation energy; Theoretical chemistry; quantum chemistry; Teoretisk kemi; kvantkemi;

    Abstract : Different aspects of porphyrin proteins have been studied with theoretical methods. For example, we have studied: - The importance of hydrogen bonds for the discrimination between carbon monoxide and molecular oxygen by myoglobin, the oxygen carrier in muscles, modelling the active site both in vacuum and in the protein matrix - The inner-sphere reorganisation energy during electron transfer for cytochromes compared to other electron-transfer proteins, such as blue copper proteins and Fe-S clusters - The role of porphyrin distortions in the reaction mechanism of ferrochelatase, the enzyme that inserts an iron ion into protoporphyrin IX to make haem - The interaction between different metal sites in ferrochelatase In these studies we have used density functional theory, classical force field methods, and a combination of quantum chemistry and molecular mechanics. READ MORE

  4. 14. Hydration of oxo anions : a combined computational and experimental structure and dynamics study in aqueous solutions

    Author : Lars Eklund; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : The structure and dynamics of several hydrated oxo anions were studied using multiple methodologies. Aqueous solutions of sulfate, sulfite, thiosulfate, peroxysulfate, selenite, selenate, hypochlorite, chlorite, chlorate, perchlorate, bromate, iodate and periodate salts were studied using large angle X-ray scattering (LAXS) and extended X-ray absorption fine structure (EXAFS) spectroscopy. READ MORE

  5. 15. Development and Implementation of Methods in Theoretical Chemistry

    Author : Jesper Wisborg Krogh; Beräkningskemi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; UO2; Electrostatic potential; Photo dissociation; Nuclear Quadrupole Moment; Relativity; RASSCF; LoProp; Method development; Parallelization; Sn; Bromoiodomethane; Theoretical chemistry; quantum chemistry; Teoretisk kemi; kvantkemi;

    Abstract : The method development research in the field of theoretical chemistry is the never ending quest for methods that are faster, gives more accurate results, and expands the possibilities. The work in this thesis is no exception to that statement. READ MORE