K2(SO4)0.63(SeO4)0.37.Te(OH)6

The title compound, dipotassium sulfate selenate/telluric acid adduct, K-2(SO4)(0.63)(SeO4)(0.47) center dot Te(OH)(6), is a solid solution in the series K2SO4 center dot Te(OH)(6)/K2SeO4 center dot Te(OH)(6). It crystallizes in the same structure as the end member K2SO4 center dot Te(OH)(6) in the space group P (1) over bar, whereas the other end-member K2SeO4 center dot Te(OH)(6) crystallizes in the space group C2/c. The structure of the solid solution consists of planes of Te( OH) 6 octahedra alternating with planes of statistically occupied XO4 tetrahedra (X = S and Se), and with K+ cations situated between the planes. The structure is stabilized by interplanar O - H center dot center dot center dot O hydrogen bonds involving all the H atoms that belong to the OH groups of the Te(OH)(6) octahedra. Both Te atoms lie on inversion centres.