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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Effective theories of finite volume QCD

Basile, Francesco January 2008 (has links)
No description available.
2

Computational studies of heavy element complexes

O'Grady, Emma Margaret January 2005 (has links)
This thesis reports the computational studies of the ground state electronic prop erties of AnOX5 n- (An=Pa, n=2 U, n=l Np, n=0 X=F, CI, Br), of C1M(PH3) 2 (M=Cu, Ag, Au, 111 ) and of MX3 (M-La-Lu, Ac-Lr X=H, F, CI, Br, I) us ing Density Functional Theory (DFT) and ab initio methods. Before presenting the results from these studies, the first chapter introduces computational studies of heavy element compounds through a discussion of selected studies taken from the literature. The second chapter introduces the electronic structure methods that were used during the course of this research. The results of this research are presented in chapters 3 to 5. Chapter 3 discusses DFT studies of the inverse trans influence (ITI) of AnOX5 n_ (An=Pa, n=2 U, n=l Np, n=0 X=F, CI, Br). These studies show that the ITI is due mainly to electronic factors at the equilibrium geometry, the 9ai molecular orbital of AnOXs n_, which is 7r* along the An-Xci5 bond, plays a key role in elongating the cis bond. In chapter 4, the metallophilic interactions of the 6d transactinide coinage metal, 111 , are presented. Comparison of the interaction energies of C1M(PH3) 2 (M=Cu, Ag, Au, 111 ), shows that with the exception of MP2, the post-HF (QCISD, CCSD and CCSD(T)) methods calculate that the interaction energies for the four complexes are approximately constant. The final results chapter (chapter 5) examines the influence of the 4f orbitals in determining the extent of pyramidality of LnX3 (Ln=La-Lu X=H, F-I) using the B3PW91 method. This study reports that the 4f orbitals reduce the extent of pyramidality via a reduction in the 5d orbital-based second-order Jahn-Teller distortion. A comparison between LnX3 and AnX3 (An=Ac-Lr X=H, F-I) is also made. The final chapter summarises the research.
3

A study into pericyclic reactions and beyond through the lens of modern valence bond theory

Blavins, Joshua James January 2003 (has links)
No description available.
4

New methods in quantum chemistry : single determinant approximations to post-Hartree-Fock and excited state wavefunctions

Richings, Gareth William January 2007 (has links)
No description available.
5

Computational chemistry as applied to electron transfer

Amini, Ata January 2003 (has links)
No description available.
6

DNA field effect transistors and silicon quantum dots

Lie, Lars Henning January 2005 (has links)
No description available.
7

Electronic spectroscopy of Van der Waals clusters and complexes

Musgrave, Adam January 2007 (has links)
No description available.
8

Quantum electrodynamical calculations of higher order energy transfer processes with molecular applications

Daniels, Gareth J. January 2005 (has links)
No description available.
9

SIMPER method for van der Waals complexes

Tulegenov, Akyl S. January 2006 (has links)
No description available.
10

High quality electron densities as a tool in Kohn-Sham theory

Allen, Mark J. January 2004 (has links)
In this thesis high quality electron densities are used to provide insight into density functional theory (DFT) and to improve the quality of DFT calculations. Chapter 1 provides an introduction to ab initio molecular wavefunction calculations with particular emphasis on the Hartree-Fock method. Chapter 2 outlines important concepts in density functional theory (DFT). This includes a discussion of the Zhao, Morrison and Parr (ZMP) method, which is the key to calculating DFT quantities from high quality densities. In Chapter 3, high quality densities are used to gain an understanding of dispersion interactions in the helium dimer. The investigation seeks to understand the correlation potentials associated with a density distortion that gives rise to the correct dispersion forces. Chapter 4 presents a study of response properties using orbitals and eigenvalues determined from high quality densities. Both magnetic and electric properties are considered and comparisons are made with conventional DFT functionals and wavefunction methods. Chapter 5 makes a comparison between Kohn-Sham eigenvalues and related properties, generated both by conventional functionals and from densities. The influence on NMR shielding constants is considered and two approaches to correcting LUMO eigenvalues are presented. In chapter 6, a DFT exchange-correlation functional determined from a lit to high quality densities is applied to study the gauche effect in 2-fluoroethylamine, 2-fluoroethanol and their protonated analogues. Conclusions are presented in Chapter 7.

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