Quaternary Supertetrahedra-Layered Telluride CsMnInTe3: Why Does This Type of Chalcogenide Tilt?

Dark-red CsMnInTe3 is synthesized by a solid-state approach using CsCl as the reactive flux. This layered compound is constructed by T-3 supertetrahedra and crystallizes in the space group C2/c with a = 12.400(7) angstrom, b = 12.400(7) angstrom, c = 24.32(2) angstrom, beta = 97.31(2)degrees, and V = 927.07(6) angstrom(3). The electrostatic interactions cause tilting of the supertetrahedra layers, and the value of the tilting angle is fixed by a structure index, beta' = 180 degrees - arccos(a/4c). Such an index is valid for all of the members in this family known to date.