ReO3 is alpha Rhenium trioxide structured and crystallizes in the cubic Im-3 space group. The structure is three-dimensional. Re6+ is bonded to six equivalent O2- atoms to form corner-sharing ReO6 octahedra. The corner-sharing octahedral tilt angles are 6°. All Re–O bond lengths are 1.90 Å. O2- is bonded in a linear geometry to two equivalent Re6+ atoms.