Cs₂(SO₄)_0.57(SeO₄)_0.43·Te(OH)₆, an adduct between dicaesium sulfate selenate and telluric acid

The title compound, dicaesium sulfate selenate-telluric acid adduct, Cs₂(SO₄)_0.57(SeO₄)_0.43·Te(OH)₆, is a solid solution in the series Cs₂(SO₄)·Te(OH)₆/Cs₂(SeO₄)·Te(OH)₆. It crystallizes in the same structure as the end member Cs₂(SeO₄)·Te(OH)₆ in space group P2₁/c, whereas the corresponding sulfate adopts another structure type and crystallizes in space group R3. The structure contains planes of statistically distributed SO₄/SeO₄ tetra­hedra alternating with planes of Te(OH)₆ octa­hedra, and with Cs⁺ cations situated between the planes. Both Te atoms lie on centres of symmetry.