Cs7In4Bi6:: A zintl phase tailored from the PbO-type layers of the parent InBi compound

The title compound was made by fusion of stoichiometric mixture of the pure elements. The structure (triclinic, <P(1)over bar>, Z = 4, a = 10.1851(4) Angstrom, b = 10.2318(7) Angstrom, c = 27.617(2) Angstrom, alpha = 94.457(7)degrees, beta = 91.462(6)degrees, gamma = 90.214(6)degrees) is based on In-centered tetrahedra of bismuth sharing edges to form folded chains. The latter are linked via In-In bonds in a rather complicated three-dimensional network. The structure can be explained as being carved out from the layered PbO-type structure of the parent group III-V compound of InBi. Cs7In4Bi6 is a wide band-gap semiconductor according to EHMO calculations and magnetic measurements.