Density functional calculations are performed to study the linear OCuO molecule in the neutral, cationic, and anionic charge states. The equilibrium bond lengths, vibrational frequencies, and electronic configurations are obtained. A theoretical assignment for the features in the photoelectronic spectrum is given at the local spin-density approximation level. Our results compare well with the available experimental results and show that the ground state of the OCuO molecule is the doublet ((2)Pi(g)).