Room-temperature crystal structure of the layered phase CuIInIIIP2S6

Abstract The room-temperature structure of CuInP 2 S 6 was determined using single-crystal X-ray diffraction. It crystallizes in the monoclinic symmetry, space group Cc , with the lattice parameters a = 6.0956(4) A , b = 10.5645(6) A , c = 13.6230(8) A , β = 107.101(3)°, V = 838.5(1) A and Z = 4 . As for CuCrP 2 S 6 and CuVP 2 S 6 , the layered structure consists of a succession of ( SCu I 1 3 In III 1 3 (P 2 ) 1 3 S ) slabs separated by empty van der Waals gaps. Within a slab, the octahedral voids defined by the ABC close-packed array of sulfur are filled by the metal cations and P 2 groups such that a triangular two-dimensional sublattice is formed by each of them. The Cu(I) ions are distributed on two inequivalent off-center sites with occupation ratios of about 0.9 and 0.1 per octahedron, and the In(III) ions are displaced from the center of their octahedra.