From crystallographic analysis of the structures CsFe2S3, Tl2PbZrS4, Tl2PbGeS4 with the 1:1 cation/anion ratio, a unified F-sublattice has been established for Cs and S in CsFe2S3. The F-sublattices for cations and anions separately were revealed for Tl2PbZrS4 (PbS structure type). Replacing a relatively large Zr4+ by à small Ge4+ atom with its tetrahedral coordination in sulfur results in increasing the unit cell volume, i.e. in decreasing the packing density of both the cations and anions in the structure of Tl2PbGeS4. “Two-dimensional” orderings of the atomic positions typical for PbS occur in the projections of this structure with the absence of regular F- sublattices.
Key words: crystallographic analysis, large Cs+, Tl+ cations in sulfides, F-sublattices, PbS structure type, \"two-dimensional\" orderings of atomic positions.