Thesis (Ph. D.)--University of Sydney, 2003. / Title from title screen (viewed Apr. 28, 2008). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the School of Chemistry, Faculty of Science. Includes bibliographical references. Also available in print form.

Thesis (Ph. D.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004. / Includes bibliographical references (leaves 63-66). Also available in electronic version. Access restricted to campus users.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1966. / Typescript. Vita. Appendix: "Perturbation treatment of the ground state of H₂⁺" [by] William D. Lyon ... [et al.]: p. 115-120. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph.D.)--Memorial University of Newfoundland, 1997. / Bibliography: leaves 190-210.

Thesis (Ph.D.)--University of Delaware, 2010. / Principal faculty advisor: Douglas J. Doren, Dept. of Physics & Astronomy. Includes bibliographical references.

Thesis (Ph. D.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2006. / Dr. C. P. Wong, Committee Member ; Dr. C. David Sherrill, Committee Member ; Dr. Thomas M. Orlando, Committee Member ; Dr. Mostafa A. El-Sayed, Committee Member ; Dr. Robert M. Dickson, Committee Chair.

Made available in DSpace on 2015-03-03T11:52:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-07-21Bitstream added on 2015-03-03T12:06:57Z : No. of bitstreams: 1 000808608.pdf: 1523686 bytes, checksum: f545c7465c56b46cea6da94906c9f8a7 (MD5) / Os efeitos relativístico estão mais próximos de nós do que pensamos, com por exemplo: na cor do metal Ouro, no funcionamento da bateria Chumbo-ácido entre outros. Os efeitos relativísticos são mais intensos em átomos pesados, sobretudo no átomo de Ouro, desempenhando um papel essencial para a interpretação dos fenômenos de natureza quântica, visto que os seus efeitos tendem a alterar significativamente a energia e a geometria dos sistemas. Quando comparados aos resultados obtidos pela utilização de metodologias não relativísticas (HF) e quasi relativística (ZORA) podemos perceber claramente a influência das consequências da Teoria da Relatividade, como por exemplo: o acoplamento spin-órbita e a quebra da degenerescência na enrgia dos orbitais. Nesse trabalho, iremos utilizar as metodologias relativísticas de Dirac-Hartree-Fock (DHF) e Teoria do Funcional de Densidade (DFT) para o estudo de sistemas compostos por átomos de Ouro e demonstraremos que, apesar do elevado custo computacional envolvido, as metodologias relativísticas devem ser a primeira opção de escolha dada a excelente qualidade dos resultados obtidos, em propriedades geométricas eletrônicas, tais como: a distância de ligação e Afinidade Eletrônica. Particularmente no estudo da molécula de Au2 obtivemos excelente resultado para a distância de ligação, pois a divergência entre o valor teórico (utilizando-se dessas metodologias) e o valor experimental é de apenas 4,05% / Relativistic effects are clorer to up than we think, such as: gold color metal, the operation of lead-acid battery among others. Relativistic effects are more intense in heavy atoms, especially of gold atom, having an essential role for the interpretation of the phenomena of quantum nature, since their effects tend to significantly change the energy and the geometry of the systems. When compared to results obtained by using non-relativistic methods (HF) and quasi-relativistic (ZORA) we can clearly see the influence of the consequences of the theory of relativity, for example, the spinorbit coupling and the breaking of degenerte orbitals. In this work, we will use the relativistic Dirac-Hartree methodologies-Fock (DHF) and Density Functional Theory (DFT) to study systems composed of gold atoms and demonstrate that, despite the high computational cost involved, the relativistic methodologies should be the first option of choise due to excellent quality of the results obtained in geometric and electronic properties such as the bond distance and Electron Afinity. Particularly in the study of molecule Au2 excellent result obtained for the connection distance as the divergence between the theoretical valeu (using these methodologies) and the experimental value is only 4.05%

Orientador: Aguinaldo Robinson de Souza / Banca: Nelson Henrique Morgon / Banca: Alberico Borges Ferreira da Silva / Banca: Fernando Luis Barroso da Silva / Banca: Alexys Bruno Alfonso / Resumo: Os efeitos relativístico estão mais próximos de nós do que pensamos, com por exemplo: na cor do metal Ouro, no funcionamento da bateria Chumbo-ácido entre outros. Os efeitos relativísticos são mais intensos em átomos pesados, sobretudo no átomo de Ouro, desempenhando um papel essencial para a interpretação dos fenômenos de natureza quântica, visto que os seus efeitos tendem a alterar significativamente a energia e a geometria dos sistemas. Quando comparados aos resultados obtidos pela utilização de metodologias não relativísticas (HF) e quasi relativística (ZORA) podemos perceber claramente a influência das consequências da Teoria da Relatividade, como por exemplo: o acoplamento spin-órbita e a quebra da degenerescência na enrgia dos orbitais. Nesse trabalho, iremos utilizar as metodologias relativísticas de Dirac-Hartree-Fock (DHF) e Teoria do Funcional de Densidade (DFT) para o estudo de sistemas compostos por átomos de Ouro e demonstraremos que, apesar do elevado custo computacional envolvido, as metodologias relativísticas devem ser a primeira opção de escolha dada a excelente qualidade dos resultados obtidos, em propriedades geométricas eletrônicas, tais como: a distância de ligação e Afinidade Eletrônica. Particularmente no estudo da molécula de Au2 obtivemos excelente resultado para a distância de ligação, pois a divergência entre o valor teórico (utilizando-se dessas metodologias) e o valor experimental é de apenas 4,05% / Abstract: Relativistic effects are clorer to up than we think, such as: gold color metal, the operation of lead-acid battery among others. Relativistic effects are more intense in heavy atoms, especially of gold atom, having an essential role for the interpretation of the phenomena of quantum nature, since their effects tend to significantly change the energy and the geometry of the systems. When compared to results obtained by using non-relativistic methods (HF) and quasi-relativistic (ZORA) we can clearly see the influence of the consequences of the theory of relativity, for example, the spinorbit coupling and the breaking of degenerte orbitals. In this work, we will use the relativistic Dirac-Hartree methodologies-Fock (DHF) and Density Functional Theory (DFT) to study systems composed of gold atoms and demonstrate that, despite the high computational cost involved, the relativistic methodologies should be the first option of choise due to excellent quality of the results obtained in geometric and electronic properties such as the bond distance and Electron Afinity. Particularly in the study of molecule Au2 excellent result obtained for the connection distance as the divergence between the theoretical valeu (using these methodologies) and the experimental value is only 4.05% / Doutor

In this thesis calculations have been made with the Xα scattered wave (XαSW) and complete neglect of differential overlap (CNDO) methods. A common theme involves the parametrisation of the CNDO method for the heavier elements (e.g. atomic numbers greater than 10), although an initial study concerned the re-parametrisation of the CNDO method for systems based on LiF-, It is indicated that the conventional CNDO/2 parameters appear inadequate for ionic systems which involve substantial re-allocation of charge from the normal atomic states. For this application, the CHDO method was reparametrised by direct reference to a previously published near-Hartree-Fock calculation on diatomic LiF, and the suitability of the new CNDO parameters was assessed by calculations on (LiF)₂ and on clusters consisting of up 18 atoms. In independent calculations, Evarestov and Lovchikov (1977) showed these new parameters have advantages over the other sets when using CNDO-type calculations for investigating the band structure of LiF. Chapter 3 reports new XαSW calculations for some clusters formed by silver atoms; these are for Ag₇ and Ag₁₀. which simulate the (111) surface of silver, Ag₁₃ and Ag₁₉, which simulate bulk silver and two forms of Ag₇I which are designed to investigate the adsorption of iodine atoms on the (111) surface of silver. Local and total density of states curves are reported, and high coordinate atoms have been found to exhibit strong localisation OB the electronic structure. So far CNDO parametrisations are not well developed for So far CNDO parametrisations are not well developed for clusters of transition metal atoms, and in chapter 4 new CNDO parameters for silver have been obtained by comparing local and total density of states and charge distributions from CNDO calculations with those from the XαSW method for the Ag₇ cluster- The new CNDO parameters have then been used for making CNDO calculations on farther silver clusters, namely Ag₆, Ag₁₀, Ag₁₃ and Ag₁₉, and the results are compared with data from the XαSW calculations. These CNDO calculations give d-band widths in broad agreement with those from the XαSW method. The most significant difference is that the CNDO method gives less localisation on central atoms with high coordination numbers than is found from the XαSW calculations. It is suggested that this apparent deficiency of the CNDO calculations may be less serious when the clusters are being used for modelling part of a solid metal rather than for specifically investigating the properties of small metal particles. The final chapter of this thesis presents calculations on systems composed of the elements aluminium to sulphur. New calculations have been made with the XαSW method for the molecular clusters Al₇, Si₅H₁₂ and P₄, and comparisons made with experiment and with other calculations where possible. However the main reason for making these calculations has been to use the charge distributions and transition-state energies, along with information obtained previously by Salahub et al. for S₃, for deriving new CNDO parameters for the elements aluminium to sulphur. Calculations using these parameters have been tested against a new XαSW calculation made here for an Al₁₀ cluster (which simulates the (111) surface of aluminium), and against XαSW calculations made previously for P₈, P₄S₅, SiH₄, PH₃, H₂S and S0₂. This way of getting CNDO parameters seems broadly successful in these cases, and this work thereby provides a firmer basis for using results from XαSW calculations for extending the CNDO procedures systematically to a wider range of the heavier elements. / Science, Faculty of / Chemistry, Department of / Graduate