Defects in amorphous silica: Ab initio MO calculations

Abstract

SCF-MO calculations have been carried out on a number of silicon oxy-hydroxides chosen to simulate possible defects in amorphous silica. It is concluded that Si=O double bonds and four-membered SiOSiO rings are not plausible high-concentration defects. Support is provided for Galeener’s assignment of the D1 and D2 ‘‘defect’’ bands in the Raman spectrum of amorphous silica to eight- and six-membered rings, respectively.