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

      CELL PARAMETERS:    5.5659   5.6420   7.9322   90.000   89.989   90.000
      SPACE GROUP: P2_1/n    
      X-RAY WAVELENGTH:     1.541838
      Cell Volume:    249.093
      Density (g/cm3):      2.799
      MAX. ABS. INTENSITY / VOLUME**2:      4.029410734    
      RIR:      0.469
      RIR based on corundum from Acta Crystallographica A38 (1982) 733-739
               2-THETA      INTENSITY    D-SPACING   H   K   L   Multiplicity
                19.31         41.90        4.5976    0   1   1         4
                19.48         21.66        4.5566    1   0   1         2
                19.48         15.80        4.5557   -1   0   1         2
                22.42         25.56        3.9661    0   0   2         2
                22.44         56.70        3.9623    1   1   0         4
                25.12          1.42        3.5449    1   1   1         4
                25.12          2.70        3.5445   -1   1   1         4
                31.72         31.69        2.8210    0   2   0         2
                31.92         47.81        2.8033    1   1   2         4
                31.93         52.19        2.8029   -1   1   2         4
                32.16         22.27        2.7829    2   0   0         2
                35.68          4.51        2.5163    1   2   0         4
                35.98         10.82        2.4958    2   1   0         4
                37.50          5.00        2.3985    1   2   1         4
                37.50          4.35        2.3984   -1   2   1         4
                37.66          8.95        2.3885    1   0   3         2
                37.67         10.63        2.3881   -1   0   3         2
                37.79          7.68        2.3809    2   1   1         4
                37.79          5.98        2.3807   -2   1   1         4
                39.19         14.07        2.2988    0   2   2         4
                39.56          3.94        2.2783    2   0   2         2
                39.56          4.09        2.2779   -2   0   2         2
                41.04          4.57        2.1995    1   1   3         4
                41.04          1.37        2.1992   -1   1   3         4
                42.55          2.50        2.1248    1   2   2         4
                42.55          4.82        2.1246   -1   2   2         4
                42.81          1.01        2.1125    2   1   2         4
                42.81          1.80        2.1122   -2   1   2         4
                45.75         25.64        1.9830    0   0   4         2
                45.80         48.49        1.9812    2   2   0         4
                47.11          1.17        1.9292    0   2   3         4
                50.04          1.14        1.8229    1   2   3         4
                50.28          1.20        1.8148   -2   1   3         4
                50.52          1.08        1.8066    3   0   1         2
                51.28          4.60        1.7817    1   3   0         4
                51.53          4.97        1.7735    1   1   4         4
                51.57          4.91        1.7722   -2   2   2         4
                51.88          1.29        1.7625    3   1   0         4
                52.65          2.86        1.7384   -1   3   1         4
                53.24          1.58        1.7206    3   1   1         4
                56.63          3.13        1.6253    1   3   2         4
                56.63          6.24        1.6252   -1   3   2         4
                56.74          6.94        1.6223    0   2   4         4
                57.02          5.32        1.6151    2   0   4         2
                57.03          1.15        1.6148   -2   0   4         2
                57.19          5.14        1.6107    3   1   2         4
                57.20          9.69        1.6105   -3   1   2         4
                60.56          1.61        1.5290   -2   3   1         4
                60.70          1.14        1.5258    1   0   5         2
                60.90          1.14        1.5213   -3   2   1         4
                66.26          1.96        1.4105    0   4   0         2
                66.73          3.52        1.4017    2   2   4         4
                66.75          3.28        1.4015   -2   2   4         4
                67.29          1.16        1.3915    4   0   0         2
                75.58          1.04        1.2581    2   4   0         4
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       XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs
  For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.