Cesium sulfate arsenate tellurate (CsSAsTe) presents one reversible phase transition of the first-order type at 213/211 K on heating-cooling runs. Indeed, it crystallizes at T = 120 K in the monoclinic system P2(1)/c and at T = 275 K, in the trigonal system R (3) over barc. These crystal structures are built from isolated (HAsO42-, SO42-) tetrahedra and (TeO66-) octahedra, they form tunnels where Cs+ cations and some hydrogen atoms are placed. The cohesion of these structures is assured on the one hand by the interaction between Cs+ and the oxygen atoms and on the other hand, by the presence of hydrogen bonds. (C) 2015 Elsevier Ltd. All rights reserved.