Etude de la tétracoordination de l'etain dans deux orthothiostannates: Na4SnS4 et Ba2SnS4 (α)

The crystal structure of Na₄SnS₄ and Ba₂SnS₄ (α) were determined.Na₄SnS₄ crystallizes in tetragonal system, space group $\text{P}\text{4}\text{2}{}_1\text{c}$ with parameters a = 7.837 Å, c = 6.950 Å, Z = 2 and Ba₂SnS₄ (α) in the monoclinic system, space group $\text{P2}{}_1\text{c}$ with a = 8.481 Å, b = 8.526 Å, c = 12.280 Å, β = 112.97° and Z = 4.In these compounds, the crystal structure is built up from discrete orthothiostannate tetrahedra SnS₄. The structure of Ba₂SnS₄ (α) is modified K₂SO₄β type.