Formula: Al Na3 F6
Name: Cryolite
Unit cell: 5.5443 5.6391 7.9127 90.0 90.098 90.0 , V=247.39
Space group: P121/N1 (14)

Yang H , Ghose S , Hatch D M , Physics and Chemistry of Minerals , 19 (1993) p.528-544, Ferroelastic phase transition in cryolite, Na3AlF6, a mixed, fluoride perovskite: high temperature single crystal X-ray, diffraction study and symmetry analysis of the transition mechanism, Sample: T = 820 K, Note: beta angle has been altered in order to reproduce bond lengths