Sökning: "multiconfigurational"
Visar resultat 1 - 5 av 11 avhandlingar innehållade ordet multiconfigurational.
1. Multiconfigurational perturbation theory
Sammanfattning : The aim of the thesis is to analyze a method which describes the electron correlation in atoms and molecules. The method is based on Rayleigh-Schrödinger perturbation theory with a partitioning of the Hamiltonian into a fairly simple zeroth-order operator and a perturbation operator. LÄS MER
2. Studies of molecular systems with multiconfigurational methods
Sammanfattning : Research in theoretical chemistry is aimed at finding computational algorithms that produce as accurate results as possible, for as large molecules as possible, with a minimum of computational effort and to apply these methods to molecular systems of chemical interest. The most accurate theoretical methods, often referred to as ab initio methods, are derived from the fundamental laws of physics and they do not rely on any empirical information. LÄS MER
3. Fundamental interactions in transition metal reactions
Sammanfattning : Transition metal complexes that participate in homogeneous reactions often perform the role of a catalyst, facilitating novel reaction pathways. When these complexes are pushed away from their equilibrium, the arrangement of the coordinating ligands around the metal center is perturbed and new reaction pathways are opened. LÄS MER
4. Towards a multiconfigurational description of the electronic structure in solids
Sammanfattning : Materials of ionic crystals are ubiquitous in industrial chemistry.For example, materials such as cerium dioixde (CeO2) are used in both self-cleaning ovens and to clean exhaust fumes from cars.Other materials, such as titanium dioixde (TiO2) has been used in the solar-cell industry.So-called garnets are used in several lasers. LÄS MER
5. Ab initio simulations of core level spectra : Towards an atomistic understanding of the dye-sensitized solar cell
Sammanfattning : The main focus of this thesis is ab initio modeling of core level spectra with a high-level quantum chemical description both of the chemical interactions and of local atomic multiplet effects. In particular, the combination of calculations and synchrotron-based core-level spectroscopy aims at understanding the local structure of the electronic valence in transition metal complexes, and the details of the solvation mechanisms of electrolyte solutions, systems relevant for the dye-sensitized solar cell. LÄS MER
