Calculation of soft atomic potentials caused by three-center bonds in silica glass

Abstract

Properties of the SiOSi linkage stretched from 0.30 to 0.46 nm in vitreous silicon dioxide are studied with MNDO and PM3 quantum-chemical methods in an isolated cluster model. The soft atomic potential caused by the three-center bond is proved to arise in the stretched linkage. The calculated electronic structure of the three-center bond and vibrational properties of the linkage are discussed.