Structure of binary sulfides with D-2h(16) symmetry

CAS-PAN analysis for revealing close-packed crystallographic planes is perf ormed to investigate the rs str structures of a series of binary chalcogeni des containing heavy cations and having D-2h(16) symmetry with a short spac ing perpendicular to the mirror plane. For chalcogenides with complex compo sitions, complex relationships between planes are typically observed. Absol ute ordering of atoms by mirror planes generally coexists with ordering alo ng the other two directions. By analogy with simple sulfides, these structu res have cationic and anionic matrices of AA' type, that is, one-layer hexa gonal packing of trigon nets with a base plane split into two planes and wi th a doubled number of sites with respect to the number of atoms.