Villiaumite_2 Formula: Na F Name: Villiaumite Unit cell: 4.6466 4.6466 4.6466 90.0 90.0 90.0 , V=100.32 Space group: FM3M (225)
Deshpande V T , Acta Crystallographica , 14 (1961) p.794-794, Thermal expansion of sodium fluoride and sodium bromide, Note: T = 108 C, rocksalt structure