Synthesis and Crystal Structure of Pd5InSe

Pd 5 InSe has been prepared from the elements. The use of iodine as a mineralizing agent enables the synthesis of single-phase powder samples as well as of single crystals. Pd 5 InSe is stable in cold air, but reacts to give Pd, In 2 O 3 and Pd 4 Se at 400 °C. The crystal structure of Pd 5 InSe was determined from single-crystal X-ray diffraction data (space group P4=mmm, a = 4.0255(7), c = 6.972(1) Å, z(Pd2) = 0.28111(8)) and belongs to the Pd 5 TlAs-type structure with full occupation of all atomic sites. EDX analysis on the single crystal (Pd 5.0 (1)In 0.99 (3)Se 1.0 (1)) confirms the stoichiometric composition. The relationship to the cubic close packing (Cu-type structure), which may be visualized by the crystal chemical formula Pd 4 PdTlAs⃞, is proven by a Bärnighausen symmetry tree.