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Structural properties of homonuclear and heteronuclear atomic clusters : Monte Carlo simulation study

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2006
Dugan, Nazım
In this thesis study, a new method for finding the optimum geometries of atomic nanoparticles has been developed by modifying the well known diffusion Monte Carlo method which is used for electronic structure calculations of quantum mechanical systems. This method has been applied to homonuclear and heteronuclear atomic clusters with the aim of both testing the method and studying various properties of atomic clusters such as radial distribution of atoms and coordination numbers. Obtained results have been compared with the results obtained by other methods such as classical Monte Carlo and molecular dynamics. It has been realized that this new method usually finds local minima when it is applied alone and some techniques to escape from local minima on the potential energy surface have been developed. It has been concluded that these techniques of escaping from local minima are key factors in the global optimization procedure.