Tychite, hexasodium dimagnesium sulfate tetracarbonate, is a member of the northupite [Na3Mg(CO3)2Cl] group and has a framework structure consisting of four basic units: CO32- groups (3 symmetry), SO42- tetrahedra (23 symmetry), MgO6 (3 symmetry) and NaO6 octahedra (2 symmetry). Among them, the CO32-, SO42-, and MgO 6 units are regular in shape, but the NaO6 octahedron, showing three different Na-O bond lengths, is considerably distorted. The Na atoms in tychite are slightly overbonded relative to those in northupite. The Raman spectroscopic data show three and four vibration modes for the CO 32- and SO42- groups, respectively; these are comparable to the corresponding Raman modes observed in other carbonates and sulfates.
|Original language||English (US)|
|Journal||Acta Crystallographica Section E: Structure Reports Online|
|State||Published - Oct 1 2006|
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics