Structure and electronic properties of copper oxide clusters and the effect of reacting with water investigated using Monte Carlo simulations and DFT calculations

[Display omitted] •Investigates the copper oxide clusters using ab initio Monte Carlo simulations and density functional theory calculations.•The lowest-energy structures of copper oxide clusters are found to be planar or nearly planar.•The CuO4 cluster has the highest stability and is the magic cluster.•In the reactions between a single water molecule and copper oxide clusters, two types of structures developed. Copper oxide clusters are particularly effective catalysts for the formation of polychlorinated-dibenzo-p-dioxins and -dibenzofurans and other pollutants. In this study, ab initio Monte Carlo simulations and density functional calculations are performed to study the structures and electronic properties of copper oxide clusters, CuOn (n = 1–6), and their reactions with a single water molecule. The lowest-energy structures of CuOn and CuOn-water clusters for n = 1–6 are optimized using the aug-cc-pVDZ and LANL2DZ basis sets of the B3LYP functional. The lowest-energy structures of copper oxide clusters are found to be planar or nearly planar. Selected electronic properties including the binding energies, second differences of the energies, HOMO-LUMO gaps, adiabatic and vertical ionization energies, adiabatic electron affinities, reaction energies, and Bader charges are calculated and examined.