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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

Validação de novas ferramentas utilizadas em ajustes de superfícies de energia potencial

Salviano, Lucas Resende 14 August 2009 (has links)
Tese (doutorado)—Universidade de Brasília, Instituto de Física, 2009. / Submitted by Larissa Ferreira dos Angelos (ferreirangelos@gmail.com) on 2010-04-05T15:24:55Z No. of bitstreams: 1 2009_LucasResendeSalviano.pdf: 1545635 bytes, checksum: 55fc14635b60d763241b937ede710225 (MD5) / Approved for entry into archive by Lucila Saraiva(lucilasaraiva1@gmail.com) on 2010-05-18T00:44:11Z (GMT) No. of bitstreams: 1 2009_LucasResendeSalviano.pdf: 1545635 bytes, checksum: 55fc14635b60d763241b937ede710225 (MD5) / Made available in DSpace on 2010-05-18T00:44:11Z (GMT). No. of bitstreams: 1 2009_LucasResendeSalviano.pdf: 1545635 bytes, checksum: 55fc14635b60d763241b937ede710225 (MD5) Previous issue date: 2009-08-14 / Neste trabalho, apresentamos um estudo sobre a qualidade de duas novas superfícies de energia potencial (SEPs) ajustadas para o sistema Na + HF. A primeira - denominada SEP GAOT - foi ajustada utilizando-se o método GAOT, enquanto a segunda - SEP qBO - foi ajustada utilizando-se a forma analítica qBO. O objetivo desse estudo é verificar a eficácia do método de ajuste GAOT e da forma analítica qBO na construção de SEPs de sistemas reativos do tipo A + BC. Para isso, foram calculadas as probabilidades de reação do referido sistema utilizando-se as SEPs GAOT e qBO. Também foram determinadas as taxas de reação do sistema utilizando-se a SEP qBO. O sistema Na + HF foi escolhido por ter sido amplamente investigado e, consequentemente, apresentar resultados bem consolidados na literatura. Os resultados aqui obtidos foram comparados com os encontrados na literatura. As probabilidades de reação obtidas para as SEPs GAOT e qBO estão em ótimo acordo com as encontradas na literatura - SEPs GSA e BO5. As taxas de reação calculadas utilizando-se a SEP qBO concordam, para altas temperaturas, com as encontradas na literatura - SEPs GAOT, GSA e BO5. Tais resultados sugerem que o método GAOT e a forma analítica qBO podem ser utilizados como importantes ferramentas de ajuste de SEPs de sistemas colisionais reativos do tipo A + BC. ________________________________________________________________________________________ ABSTRACT / In this work, we present a study about the quality of two new potential energy surfaces (PES) tted to the Na+HF system. The rst PES { named GAOT PES { was tted using the GAOT method, while the second one was tted using the qBO analytical form. The objective of this work is to verify the eectiveness of the GAOT method and the qBO analytical form in tting A + BC reactive system PES. To do this, we calculated the reactive probabilities (RP) using the GAOT PES and the qBO PES. The thermal rate constants (TRC) of the Na+HF system were also determined using the qBO PES. The Na + HF system was chosen because it has been widely investigated and, consequently, it presents consolidated results in the literature. The results were compared with those found in the literature. The qBO and GAOT RP are in excellent agreement with the RP found in the literature { GSA and BO5 RP. The qBO TRC agree with those found in the literature { GAOT, GSA and BO5 TRC { for high temperatures. These results suggest that the GAOT method and the qBO analytical form can be used as important tools of adjustment of A + BC reactive system PES.

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