Local molecular orbitals and hyper-susceptibility of TeO2 glass

The dielectric properties of the glassy telluria have been modeled and studied via the ab initio calculations of the linear- and hyper-polarizabilities of chain-like (TeO2)n clusters. By using the localized molecular orbitals approximation (GAMESS program), it is shown that their linear polarizability is mainly associated with the tellurium atom lone pairs and with the Te–O–Te bridges, whose contributions are comparable. On contrary, the bridge contributions unequivocally dominate the hyperpolarizability value (providing 75% of this) whereas the role of the lone pair on tellurium atoms is minimal (5%). The same estimations can be obtained for the relevant characteristics of TeO2 glass.