Heklaite
Diffraction data computed using the structure from the paper listed below,
along with the cell parameters refined from the powder pattern of R090034
      Fischer J, Kramer V
      Materials Research Bulletin 26 (1991) 925-930
      Crystal structure of KNaSiF_6_
      Locality: synthetic

      CELL PARAMETERS:   9.337492   5.500887   9.791165   90.00000   90.00000   90.00000
      SPACE GROUP: Pnma
      X-RAY WAVELENGTH:     1.541838
      MAX. ABS. INTENSITY / VOLUME**2:      8.077592381
               2-THETA      INTENSITY    D-SPACING   H   K   L
                13.16          9.91        6.7573    1   0   1
                18.18         22.39        4.8956    0   0   2
                18.56          1.01        4.7958    0   1   1
                19.06          8.30        4.6687    2   0   0
                20.54         51.63        4.3358    1   0   2
                20.87         69.88        4.2660    1   1   1
                26.22         43.64        3.4052    1   1   2
                26.43         42.27        3.3786    2   0   2
                26.69        100.00        3.3453    2   1   1
                29.03          2.82        3.0809    1   0   3
                30.17          8.47        2.9662    3   0   1
                31.93          9.80        2.8069    0   1   3
                32.60         15.40        2.7504    0   2   0
                34.39         10.91        2.6108    3   1   1
                35.27          2.23        2.5475    1   2   1
                37.42          1.66        2.4056    2   1   3
                37.54          1.93        2.3979    0   2   2
                38.01          1.93        2.3698    2   2   0
                38.00          3.13        2.3703    3   1   2
                38.04          2.70        2.3678    1   0   4
                38.60          2.21        2.3344    4   0   0
                39.15         24.35        2.3033    2   2   1
                40.06         19.43        2.2524    3   0   3
                41.56          5.06        2.1749    1   1   4
                41.70          1.42        2.1679    2   0   4
                42.08          1.51        2.1489    4   1   0
                42.41          1.65        2.1330    2   2   2
                42.95          4.25        2.1071    4   0   2
                43.13          8.46        2.0989    4   1   1
                44.17         42.46        2.0518    1   2   3
                44.97          3.44        2.0169    2   1   4
                44.98         24.34        2.0168    3   2   1
                46.16          1.97        1.9677    4   1   2
                47.27         11.18        1.9241    3   0   4
                47.44          2.36        1.9176    2   2   3
                47.47          9.72        1.9165    1   0   5
                47.92         10.97        1.8996    3   2   2
                49.43          5.07        1.8448    0   1   5
                49.73          5.87        1.8344    5   0   1
                50.26         13.83        1.8162    3   1   4
                50.57          7.32        1.8058    2   0   5
                50.90          2.62        1.7948    4   1   3
                51.36          4.70        1.7798    4   2   0
                52.46          1.02        1.7449    5   0   2
                52.54          2.29        1.7426    3   2   3
                54.34          1.53        1.6888    1   3   2
                54.60          7.65        1.6814    2   3   1
                54.91          1.68        1.6727    4   2   2
                55.25          2.42        1.6632    5   1   2
                55.46          1.11        1.6575    3   0   5
                57.68          1.07        1.5986    0   3   3
                58.56          5.09        1.5766    3   2   4
                58.73          1.98        1.5724    1   2   5
                59.26          3.04        1.5597    3   3   1
                59.40          1.29        1.5562    6   0   0
                59.46          1.27        1.5548    5   1   3
                60.07          2.13        1.5405    2   0   6
                61.71          1.02        1.5035    3   3   2
                61.98          1.56        1.4975    6   1   0
                62.57          1.48        1.4847    5   0   4
                62.78          1.15        1.4803    6   1   1
                63.11          5.49        1.4734    5   2   2
                64.38          1.06        1.4474    4   1   5
                64.77          1.33        1.4395    4   2   4
                66.65          1.94        1.4034    0   2   6
                66.58          1.35        1.4047    6   0   3
                67.02          1.10        1.3964    5   2   3
                67.75          1.50        1.3832    4   3   2
                68.20          5.20        1.3752    0   4   0
                69.57          1.46        1.3515    5   0   5
                70.01          5.62        1.3440    2   2   6
                70.34          2.13        1.3385    0   3   5
                71.01          4.38        1.3274    3   3   4
                71.95          1.78        1.3124    5   1   5
                72.39          2.99        1.3054    6   2   2
                72.95          1.29        1.2969    5   3   1
                74.49          1.50        1.2737    2   4   2
                75.16          1.39        1.2640    5   3   2
                76.08          2.62        1.2510    6   2   3
                78.50          1.42        1.2184    6   0   5
                81.03          1.21        1.1865    6   3   0
                82.23          1.35        1.1723    4   1   7
                86.35          1.14        1.1265    7   2   3
                87.09          1.44        1.1188    3   4   4
                87.15          2.43        1.1182    0   2   8
                87.15          2.43        1.1182    0   2   8
       XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs
  For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.