Diatomic dications corresponding to stable neutral species (e.g. H22+ formed by removal of two electrons from H2) often decay quickly into two singly charged particles (H+), due to the loss of electrons in bonding molecular orbitals. Energy levels of diatomic dications can be studied with good resolution by measuring the yield of pairs of zero-kinetic-energy electrons from double photoionization of a molecule as a function of the photoionizing wavelength (threshold photoelectrons coincidence spectroscopy - TPEsCO). The He22+ dication is kinetically stable.
An example of a stable diatomic dication which is not formed by oxidation of a neutral diatomic molecule is the dimercury dication Hg22+. An example of a polyatomic dication is S82+, formed by oxidation of S8 and unstable with respect to further oxidisation over time to form SO2.