Benstonite
Diffraction data computed using the structure from the paper listed below,
along with the cell parameters refined from the powder pattern for R050484
      Effenberger H
      Neues Jahrbuch fur Mineralogie, Abhandlungen 136 (1979) 326-337
      Kristallstruktur und chemische formel des benstonits, Ba6Ca6Mg(CO3)13

      CELL PARAMETERS:   18.27125   18.27125   8.700133   90.00000   90.00000   120.0000
      SPACE GROUP: R-3
      X-RAY WAVELENGTH:     1.541838
               2-THETA      INTENSITY    D-SPACING   H   K   L
                 9.71          7.05        9.1356    1   1   0
                11.63          5.96        7.6237    1   0   1
                15.16          3.59        5.8533    0   2   1
                16.83          6.30        5.2745    3   0   0
                18.02          8.09        4.9285    2   1   1
                19.45          6.03        4.5678    2   2   0
                21.20         16.90        4.1944    0   1   2
                22.71         45.09        3.9183   -1   4   1
                22.71          1.03        3.9183    1   3   1
                23.35          1.80        3.8119    2   0   2
                24.74         11.15        3.6011    4   0   1
                25.81          5.16        3.4529    4   1   0
                26.62          1.01        3.3502    5  -2   1
                26.62          8.88        3.3502    3   2   1
                28.91         99.80        3.0895    3   1   2
                30.84          1.17        2.9000    0   0   3
                31.64          1.29        2.8280   -2   6   1
                32.39          2.55        2.7641    1   1   3
                35.07          2.93        2.5591    5   0   2
                35.43         32.01        2.5338    2   5   0
                35.43          1.68        2.5338    5   2   0
                35.32          5.56        2.5412    0   3   3
                36.46          2.71        2.4642    6  -2   2
                36.71         10.09        2.4483    4  -2   3
                37.81          1.03        2.3792    1   5   2
                37.81          1.25        2.3792   -1   6   2
                38.72          4.13        2.3253   -1   7   1
                40.40          5.95        2.2326    3   4   2
                40.62         10.55        2.2207   -1   5   3
                41.26          1.54        2.1878    3   5   1
                41.26          4.90        2.1878   -3   8   1
                42.48         24.78        2.1277    6   2   1
                42.48          1.18        2.1277    8  -2   1
                42.85          4.43        2.1101    7  -1   2
                43.16          4.43        2.0959    7   1   0
                44.31          3.00        2.0441    2   1   4
                45.20          3.18        2.0058    8  -3   2
                45.49          3.81        1.9936    6   3   0
                46.34         10.50        1.9592   -2   8   2
                46.34          5.42        1.9592    2   6   2
                46.60         14.08        1.9488   -1   4   4
                47.65         10.51        1.9081    7  -2   3
                47.65          9.29        1.9081    2   5   3
                47.71          4.16        1.9059    4   0   4
                48.21          5.30        1.8871   -2   9   1
                48.80          4.42        1.8658    3   2   4
                52.92          3.46        1.7296    0   1   5
                53.96          1.31        1.6987    7   1   3
                55.96          1.48        1.6428    6   3   3
                56.46          5.87        1.6294    1   9   1
                56.46          6.19        1.6294   11  -5   1
                56.91          1.68        1.6175    3   1   5
                59.64          5.02        1.5499   10  -1   2
                59.64          5.14        1.5499    5   6   2
                59.80          1.06        1.5459   10  -5   3
                59.85          2.26        1.5447    6   2   4
                60.29          1.37        1.5347   11  -2   1
                61.67          1.15        1.5034    0   9   3
                62.15          1.19        1.4931    5   7   1
                62.60          1.62        1.4835    2   8   3
                62.57          1.49        1.4840    1   5   5
                63.58          3.65        1.4629    9   3   0
                64.46          1.53        1.4449   -2   9   4
                64.39          1.13        1.4463    3   4   5
                65.32          1.17        1.4281   11  -4   3
                66.19          1.66        1.4114    7  -1   5
                66.89          1.18        1.3981    0   3   6
                67.96          2.29        1.3788    8  -3   5
                68.83          1.44        1.3634    2   6   5
                68.83          1.01        1.3634   -2   8   5
                69.57          1.60        1.3507   10   2   2
                69.73          2.47        1.3481   12  -6   3
                70.59          1.68        1.3337    1  10   3
                70.39          1.15        1.3369   -1   5   6
                71.50          1.39        1.3190    6   5   4
                71.50          1.85        1.3190    1   9   4
                71.50          1.73        1.3190   11  -5   4
                72.16          1.29        1.3085    9   4   2
                72.31          2.04        1.3061   -3  12   3
                72.31          2.17        1.3061    9   3   3
                73.86          1.11        1.2825   -3  13   2
                74.06          1.36        1.2796   10   0   4
                74.92          4.92        1.2669    4  10   0
                74.90          1.19        1.2672   11  -2   4
                76.59          1.85        1.2435    5   7   4
                79.47          1.10        1.2054   13   0   1
                82.20          1.92        1.1722    0  13   2
                82.16          1.29        1.1726    6   3   6
                82.16          1.29        1.1726    6   3   6
       XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs
  For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.