Zr6STe2 - a zirconium-rich sulfide telluride with a Zr3Te partial structure of the Re3B type

Zr6STe2 is accessible through the reduction of a mixture of ZrTe2 and ZrS2 with zirconium in fused tantalum tubes at 1520 K. The spatially averaged cr ystal structure of Zr6STe2 is described in the space group Cmcm, a = 377.81 (4), b = 1156.4(1), c = 887.96(8), Z = 2, Pearson symbol oC18, 320 reflexio ns (I > 2 sigma (I)), 22 variables, R-w(T) = 0.088. Zr6STe2 crystallizes in a unique structure type, which can be seen as a filled Re3B type structure . The tellurium atoms are surrounded by nine zirconium atoms situated at th e vertices of a distorted, tricapped trigonal prism. The Zr9Te tetrakaideca hedra are connected by common triangular prism faces parallel [100], edges approximately along [001] and common vertices along [010], thus forming a t hree-dimensional tetrakaidecahedral network (3)(infinity)[Zr9/3Te] which is decisively stabilized by homonuclear Zr-Zr-interactions. The tetrakaidecah edra are arranged in such a way, that Zr-6 octahedra occur. The octahedra a re arranged into layers by sharing edges parallel [100] and vertices along [001]. As a result of a distortion of the structure, every second octahedro n is expanded to such an extent as to be able to smoothly accommodate sulfu r atoms. According to the modulation of the diffraction intensities, the va cancy ordering in adjacent layers of octahedra occurs independently of each other.