Monday, 31 October, 2011, 17:12
Posted by Marcela Trybula
In October was done:Posted by Marcela Trybula
Oral presentation of master thesis results. The aim of the thesis was to investigate the changes in bond length and order, depending on molecule size and bond location in the chains of polyyne and cumulene. Using the ETS-NOCV method of Mitoraj , bonds in the centre of polyyne and cumulene chains were qualitatively and quantitatively described. Another subject of investigation was influence of change in the length of central bond in the shortest polyyne and cumulene chains on the change of bond orders. DFT/BP calculations carried out in this work allowed to find the length of cumulene chain for which the alternation of bonds reappears. The reappearance of bond alteration is clear for molecules counting more than 104 carbon atoms, which is much more than for similar calculations carried out with SCC-DFTB or DFT/B3LYP methods. Such a result shows a significant quantitative difference between various calculation methods. In spite of these quantitative differences, the results obtained in this work were qualitatively consistent with the results obtained with other methods, e.g. SCC-DFTB, DFT/B3LYP . A significant part of this thesis was the application of ETS-NOCV methodology to obtain quantitative information about the participation of σ and π components in the investigated chemical bonds; this kind of information was inaccessible by other methods of charge and bond order analysis.
Doctoral thesis concerned the description of solution model based on the free volume theory [Lupis,1956], Shimoji [Shimoji,1957]. Form initial theoretical studies come from necessity to define a new factor beta and the configuration entropy can be also developed. Comparing of both ideas, namely Tanaka and PhD student, was shown evidently clear good path of taking measures to extension of applied model in case of simulation the excess thermodynamic functions (Gibbs energy and entropy). Unfortunately, each model has some constraint, which are limited to using for every metallic solutions.
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