Mechanism of interconversion among radiation-induced defects in amorphous silicon dioxide

We here present a series of ab initio quantum-chemical calculations on clus ters of atoms modeling several oxygen-deficiency-related defects in amorpho us silica and illustrate how these defect centers will change their atomic configurations upon photoionization. We first give theoretical evidence tha t structural conversion from a neutral oxygen monovacancy to a divalent Si defect is possible. explaining the observed photoluminescence properties as sociated with these defects.