Molecular dynamics study of amorphous titanium silicate

The molecular dynamics computer simulation was used to study the local structure of titanium in silica glass. The empirical potential function used in previous simulations of other glasses performed in our lab was extended to study titanium in silica. The results indicate that at low concentrations (<10 mol% TiO₂), titanium is mainly tetrahedral in bulk silica. At higher TiO₂ concentrations, titanium coordination increases. Slower quench rates enhance these trends observed in the changes in titanium coordination. A cluster of overcoordinated species similar to rutile was found in TiO₂: 9SiO₂ and is discussed within the constraints of the MD experiment. Overall, the MD result are consistent with EXAFS data of bond lengths and coordination numbers of TiO₂ in titanium silicate glasses.