Sökning: "multiconfigurational methods"
Visar resultat 1 - 5 av 7 avhandlingar innehållade orden multiconfigurational methods.
1. 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
2. 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
3. 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
4. Theoretical Studies on Electronic Structure, Spectra and Conductivity of Pristine and Alkali Doped Polyacetylene
Sammanfattning : The present thesis is a theoretical investigation of the electronic properties of linear polyenes to get an insight into conductive phenomena in pristine and doped polyacetylene. Conductivity in polyacetylene is a complex phenomena and cannot be treated within simple band models. LÄS MER
5. Extending the Reach of Accurate Wavefunction Methods
Sammanfattning : Multiconfigurational quantum chemistry methods, and especially the multiconfigurational self-consistent field (MCSCF) and multireference perturbation theory (MRPT2), are powerful tools, particularly suited to the accurate modeling of photochemical processes and transition metal catalysis. However, they are limited by their high computational cost compared to other methods, especially density functional theory. LÄS MER
