Re4As6S3, a thio-spinel-related cluster system

We have synthesized a new compound with formula Re4As6S3 and characterized its crystal structure by Rietveld powder diffraction methods. Re4As6S3 crystallizes in an face-centered cubic unit cell, space group <f>F4¯3m</f> (no. 216), with lattice constant <f>a=9.8608(1)</f> A˚ and <f>Z=4</f>. The rhenium atoms form tetrahedral clusters linked via tetrahedral arsenic clusters to produce an NaCl-type arrangement. The oxidation state of rhenium is IV and the number of electrons shared by the rhenium atoms in the cluster is 12. The structure is based on an ordered defect thio-spinel A(1−x)B2X4 where the B-type atoms form tetrahedral clusters. [Copyright &y& Elsevier]