We report the results of a theoretical study of sequential oxidation of gallium oxide clusters from Ga 3 O 4 to Ga 3 O 8 . These results, based on density functional theory calculations, find the ground state of the neutral clusters to be in the lowest spin state with nearly the same binding energy of 3.5 eV per atom. Electron affinity, ionization potential and HOMO–LUMO gap values of these oxygen-rich clusters show an oscillatory trend which may be due to the fact that sequential oxidation as well as addition (and removal) of an electron leads to significant changes in the geometry of the respective neutral clusters.