Redetermination of β-Al₂TiO₅ obtained by melt casting

β-Al₂TiO₅ (dialuminium titanium penta­oxide), grown by rapid cooling of a melt of equimolar amounts of Al₂O₃ and TiO₂, adopts the same overall structure as that crystallized by more conventional methods, such as sintering. Nevertheless, re­investigation of this structure has resulted in an improved structure model with previously unknown site preferences determined. Ti prefers the slightly more regular 4c octa­hedral site, leaving more room for Al at the 8f octa­hedral site. The formula has been determined as ^[4c][Al_0.626 (7)Ti_0.374 (7)]^[8f][Al_0.687 (3)Ti_0.313 (3)]₂O₅.