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We computed the atomic shift sizes of the closest adjacent atoms adjoining the (001) surface <i>F</i>-center at ABO₃ perovskites. They are significantly larger than the atomic shift sizes of the closest adjacent atoms adjoining the bulk <i>F</i>-center. In the ABO₃ perovskite matrixes, the electron charge is significantly stronger confined in the interior of the bulk oxygen vacancy than in the interior of the (001) surface oxygen vacancy. The formation energy of the oxygen vacancy on the (001) surface is smaller than in the bulk. This microscopic energy distinction stimulates the oxygen vacancy segregation from the perovskite bulk to their (001) surfaces. The (001) surface <i>F</i>-center created defect level is nearer to the (001) surface conduction band (CB) bottom as the bulk <i>F</i>-center created defect level. On the contrary, the SrF₂, BaF₂ and CaF₂ bulk and surface <i>F</i>-center charge is almost perfectly confined to the interior of the fluorine vacancy. The shift sizes of atoms adjoining the bulk and surface <i>F</i>-centers in SrF₂, CaF₂ and BaF₂ matrixes are microscopic as compared to the case of ABO₃ perovskites.