We have performed
Monte Carlo simulated annealing simulations and density functional theory calculations to study the structures and stabilities of copper oxide clusters, Cu
=1-4). We determined the lowest energy structures of neutral, positive and negatively charged copper oxide clusters using the B3LYP/LANL2DZ model chemistry. The geometries are found to undergo a structural change from two- to three-dimensions when
= 4 in the neutral clusters. We have investigated the size dependence of selected electronic properties of the binding energies, second differences of the energy, ionization potentials, electron affinities, and HOMO-LUMO gaps. We also have investigated fragmentation channels and charge distributions.