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 = 673 K
_database_code_amcsd 0007743
5.5022 5.6284 7.8725 90 90.055 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 .01945 .01900 .01648 -.00025  .00024 -.00100
Na1       0     0    .5 .03430 .03111 .02897 -.00549 -.00115  .00182
Na2  -.0093 .4576 .2517 .04924 .04434 .04934 -.00780  .00013  .00104
F1    .0944 .0398 .2180 .05013 .05849 .02056  .00215 -.00719 -.00530
F2    .2310 .3262 .5423 .03498 .03957 .04757 -.01588  .00704 -.00164
F3    .1651 .2668 .9430 .04057 .03349 .05550 -.01306  .00131  .00830