#52
Pnna
Example – Stannous tungstate, SnWO4
Stannous tungstate: Properties, crystal structure and relationship to
ferroelectric SbTaO4 type compounds
Jeitschko W., Sleight A.W.
Acta Crystallographica B30 (1974) 2088-2094
CIF
http://rruff.geo.arizona.edu/AMS/download.php?id=10518.cif&down=cif
WO6 octahedra (grey)
bent SnO2 units (blue)
The Fascination of Crystals and Symmetry 