Ba2Ti2Si2O9F2, a new titanium silicate

Dibarium dititanium difluoride dioxide heptaoxidodisilicate, Ba₂Ti₂Si₂O₉F₂, is a new edge‐sharing titanate with a unique titanium silicate framework. All atoms in the structure are in general positions. Titanium oxyfluoride octahedra combine with silicon tetrahedra to form a double stacked chain, which is the base unit of the layered framework. The Ba atoms lie in channels that extend along the a axis.