Crystal structures of gold, silver, and sodium chalcogenides: Sphenoidal interpretation

The crystal structures of 13 chalcogenides of Na, Au(I), and Ag(I) in the Na2−n(Au,Ag)n(S,Se,Te) series, where 0 ≤ n ≤ 2, are interpreted from unified positions based on the sphenoidal representation. Its essence is in the consideration of the entire crystal space (with packing X atoms in the framework of close-packing, body-centered, or hybrid schemes) as a set of elementary space units (sphenoids). Unified one-dimensional associates of sphenoids, the so-called basic rods, with sets of possible atomic positions in them are selected for all structures. The mutual effect of the dimensional and stoichiometric ratios of all components on the features of filling rod positions is analyzed. New possibilities in the crystallochemical and crystal-geometry analysis of inorganic compounds whose structures are characterized by a relatively uniform distribution of atoms are demonstrated by the example of chalcogenides.