Quenching of diamagnetic color centers at the MgO surface

The interaction between the O2 molecule and the neutral oxygen vacancy (FS centers) located at the (0 0 1) MgO surface has been studied computationally, at the Hartree–Fock (HF) and density functional theory (DFT) levels, employing the molecular cluster approach. It has been found that, at short distances from the surface, a double electron transfer from the surface to the admolecules occurs, with the formation of peroxo O22− species. The process is highly thermodynamically favored with respect to the reactants (FS + O2).