Sodium magnesium sulfate decahydrate,Na2Mg(SO4)2·10H2O,a new sulfate salt

The structure of synthetic disodium magnesium disulfate decahydrate at 180 K consists of alternating layers of water‐coordinated Mg(H₂O)₆]²⁺ octahedra and Na₂(SO₄)₂(H₂O)₄]²⁻ sheets, parallel to 100]. The Mg(H₂O)₆]²⁺ octahedra are joined to one another by a single hydrogen bond, the other hydrogen bonds being involved in inter‐layer linkage. The Mg²⁺ cation occupies a crystallographic inversion centre. The sodium–sulfate sheets consist of chains of water‐sharing Na(H₂O)₆]⁺ octahedra along b, which are then connected by sulfate tetrahedra through corner‐sharing. The associated hydrogen bonds are the result of water–sulfate interactions within the sheets themselves. This is believed to be the first structure of a mixed monovalent/divalent cation sulfate decahydrate salt.