On structures, properties and chemical bond of Te-Se-I glass and of adding As,Ge elements one

Te-Se glass and adding As,Ge elements to it are studied with Selt-Consistent-Field Discrete Variatioal X(a) (SEF-DV-X(a)), one of the molecule orbital calculating methods in quantum chemistry. The chemical bonding is used to discuss the relations between structures and properties with the varations of compositions of the glasses. The calculated results show that the strength of covalent and ionic bonds are both in the order of Ge-Se > As-Se > Te-Se, which is consistent with the experimental result of the glass-transition temperature (T-g) of the corresponding grasses. The Te-I bond in which I atom is one-coordinate is stronger than that in which I atom is two-coordinate, As-I and As-As bonds are both stronger than the two types of Te-I bonds. The waek Te-I bonds have been replaced by the stronger As-I and As-As bonds, which is just the reason why As addition in TeX glasses can obviously improve the thermal and chemical properties.