[en] The methods of infrared absorption. Hall effect, and deep-level transient spectroscopy are used to study the complexes that consist of a vacancy and two oxygen atoms (the vacancy-dioxygen complexes, VO₂) in irradiated n-Si crystals with various levels of doping. The previously observed bistability of VO₂ is confirmed and evidence is provided for electrical activity of this defect in the metastable configuration VO*₂. It is established that the defect with this configuration features an acceptor level located at E_C - 0.06 eV. It is shown that the absorption bands at 967 and 1023 cm^-1 are caused by the negatively charged VO*₂ state, while the bands peaking at 928 and 1004 cm^-1 correspond to the neutral charge state of the defect