Données cristallographiques sur cinq nouveaux tétramétaphosphates du type M^IIM^I₂P₄O₁₂

Chemical preparations and crystal data are described for five new tetrametaphosphates: CaK₂P₄O₁₂, PbK₂P₄O₁₂, PbRb₂P₄O₁₂, Pb(NH₄)₂P₄O₁₂ and PbTl₂P₄O₁₂. All of them are tetragonal and isotypic with SrK₂P₄O₁₂. The space group is I with Z = 2.