Halbantiperowskite II: zur Kristallstruktur des Pd 3 Bi 2 S 2

Halfantiperovskites II: on the Crystal Structure of Pd 3 Bi 2 S 2 The crystallographic structure of Pd 3 Bi 2 S 2 was determined from x‐ray diffraction data and compared to parkerite (Ni 3 Bi 2 S 2 ), shandite (Ni 3 Pb 2 S 2 ), and a high pressure form of laflammeite (Pd 3 Pb 2 S 2 ). For Pd 3 Bi 2 S 2 the structure type of corderoite, Hg 3 S 2 Cl 2 ( I 2 1 3) was found that represents a cubic variant ( a = 8,3097(9) Å) of the parkerite structure. It turns out to be a structural antitype of the low temperature cubic modification of K 2 Sn 2 O 3 , analogously to the previously investigated type‐antitype relation of shandit to high‐temperature K 2 Sn 2 O 3 . The crystal structures are derived from perovskites AB O 3 and antiperovskites M 3 AX with only half of the O‐ and M ‐sites being occupied. The M = Ni, Pd site ordering in shandite and parkerite type compounds is discussed in terms of ordered half antiperovskite ( HAP ) structures M 3/2 A S (A = Bi, Pb). The electronic band structure of Pd 3 Bi 2 S 2 is calculated within the framework of density functional theory. The compound is found to behave metallic while K 2 Sn 2 O 3 and corderoite are semiconductors. The bonding is analysed in terms of covalently bond [Pd 3 S 2 ] δ− networks as proposed for [Sn 2 O 3 ] 2− and [Hg 3 S 2 ] 2+ .