Computational Studies of Transition Metal Nanoalloys The focus of this thesis is the computational modelling of transition metal bimetallic (nanoalloy) clusters. More specifically the study of Pd Pt Ag Pt Au Au and Pd Au as a few tens of atoms in the gas phase. The author used a combination of global optimization techniques coupled with a Gupta type empirical many body potential and Density Functional Theory (DFT) calculations to study the structures bonding and chemical ordering as well as investigate the chemisorptions of hydrogen and carbon monoxide on bimetallic clusters. This research is highly relevant to experimental catalytic studies and has resulted in more than seven publications in international journals.