Sökning: "cluster correlation"

Visar resultat 6 - 10 av 97 avhandlingar innehållade orden cluster correlation.

1. 6. On the role of the electron-electron interaction in two-dimensional quantum dots and rings

   Författare :Erik Waltersson; Eva Lindroth; Stephanie Reimann; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum dot; quantum ring; quantum dot molecule; electronic structure; two-dimensional; many-body physics; many-body perturbation theory; coupled cluster; coupled cluster singles and doubles; quantum logical gates; quantum computing; quantum control; quantum control algorithm; Electronic structure; Elektronstruktur; fysik; Physics;

   Sammanfattning : Many-Body Perturbation Theory is put to test as a method for reliable calculations of the electron-electron interaction in two-dimensional quantum dots. We show that second order correlation gives qualitative agreement with experiments on a level which was not found within the Hartree-Fock description. LÄS MER

3. 7. Autoionizing states and their relevance in electron-ion recombination

   Författare :Dragan Nikolić; Eva Lindroth; Gleb Gribakin; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Electron-ion recombination; Autoionization; Electron correlation calculations; Doubly excited states; Relativistic many-body perturbation theory; Coupled-cluster methodology; Intruder state problem; Physics; Fysik;

   Sammanfattning : Atomic physics plays an important role in determining the evolution stages in a wide range of laboratory and cosmic plasmas. Therefore, the main contribution to our ability to model, infer and control plasma sources is the knowledge of underlying atomic processes. LÄS MER

4. 8. New Cu-I cluster compounds with luminescent properties

   Författare :Ehsan Jalilian; Sven Lidin; Torbjörn Gustafsson; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Copper I iodide; structure determination; luminescence; TDDFT; Materials chemistry; Materialkemi; Materials Chemistry; materialkemi;

   Sammanfattning : The aim of this thesis has been to investigate how the synthesis route, choice of solvent and counter-ions effects the crystallization of Cu(I)I systems, and to investigate the correlation between the structure and luminescence properties of the systems. In order to do so a series of compounds based on an anion containing Cu(I)I, stabilized by organic cations have been produced. LÄS MER

5. 9. High altitude ion heating observed by the Cluster spacecraft

   Författare :Martin Waara; Hans Nilsson; Kristina Lynch; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Space physics; Rymdfysik; rymd- och plasmafysik; Space and Plasma Physics;

   Sammanfattning : This thesis deals with heating of outowing oxygen ions at high altitude above the polar cap using data from the Cluster spacecraft. oInospheric plasma may flow up from the ionosphere but at velocities which are low enough that the ions are still gravitationally bound. For the ions to overcome gravity, further acceleration is needed. LÄS MER

7. 10. Physisorption of CO and N2O on ceria surfaces

   Författare :Carsten Müller; Kersti Hermansson; Konstantin Neyman; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ceria; carbon monoxide; nitrous oxide; embedded cluster; physisorption; method of increments; CCSD T ; vibrational frequencies; Quantum chemistry; Kvantkemi; Quantum Chemistry; kvantkemi;

   Sammanfattning : Physisorption of CO and N2O on surfaces of ceria (CeO2) was investigated by means of high-level quantum-mechanical embedded cluster calculations. Both systems have high relevance in the field of environmental chemistry and heterogeneous catalysis. LÄS MER