No easy set of struccture data but some info: there is apparently a continuous solid solution series between Fe2O3 and FeTiO3 (ilmenite) (likely some subtle ordering sets in at some composition). But on the Fe rich side you will basically have a hematite pattern. Likely there is also not stoichiometric composition "Fe9TiO15" but it is chemical formula description of a Fe rich composition of the solid solution.