Murrell-Mottram empirical atomistic many-body and Gupta n-body potentials have been used to study various aspects of the cluster chemistry of copper, silver, gold and nickel. Simulated annealing techniques have been used to search for the global minima of the four metals with up to 55 atoms. Icosahedral, decahedral, octahedral, hexagonal closed packed and hexagonal prismatic structures were found. The gold clusters show some rearrangements and distortions from ideal geometries. Polyhedral cluster calculations up to 1 500 atoms predict that icosahedra and truncated octahedra are particularly stable. Calculations on the structures of copper-gold alloy clusters show that gold atoms prefer to occupy the surface of the cluster. A simple approximation to model the passivation of gold clusters by thiol ligands predicts that for 55 atoms the passivated cuboctahedron is more stable than the icosahedron, the reverse of the order for the bare clusters. Molecular dynamics simulations of gold adatoms on the gold (111) surface and of the impact of a 55 atom gold cluster with the gold (111) surface have been performed.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:368419 |
| Date | January 2000 |
| Creators | Wilson, Nicholas Thomas |
| Publisher | University of Birmingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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