Cryolite
Yang H, Ghose S, Hatch D M
Physics and Chemistry of Minerals 19 (1993) 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 = 860 K
_database_code_amcsd 0007747
5.5659 5.6420 7.9322 90 89.989 90 P2_1/n
atom      x     y     z B(1,1) B(2,2) B(3,3)  B(1,2)  B(1,3)  B(2,3)
Al        0     0     0 .02525 .02643 .02471  .00104 -.00011  .00038
Na1       0     0    .5 .04714 .04335 .04392 -.00400 -.00164  .00102
Na2  -.0065 .4694 .2520 .06677 .07038 .07084 -.00877 -.00089  .00240
F1    .0838 .0313 .2170 .07780 .09965 .03284  .00312 -.01190 -.00855
F2    .2356 .3231 .5387 .05290 .05871 .07926 -.02581  .01333 -.00187
F3    .1687 .2638 .9507 .06351 .04812 .09296 -.02010  .00034  .01992