Prehnite
Diffraction data computed using the structure from the paper listed below,
along with the cell parameters refined from the powder pattern for R050410
      Papike J J, Zoltai T
      American Mineralogist 52 (1967) 974-984
      Ordering of tetrahedral aluminium in prehnite, Ca2(Al,Fe)[Si3AlO10](OH)2

      CELL PARAMETERS:   4.626837   5.483938   18.47614   90.00000   90.00000   90.00000
      SPACE GROUP: Pncm
      X-RAY WAVELENGTH:     1.541838
               2-THETA      INTENSITY    D-SPACING   H   K   L
                16.87         21.64        5.2573    0   1   1
                19.18         29.30        4.6268    1   0   0
                19.22          2.93        4.6190    0   0   4
                21.48          8.72        4.1370    1   0   2
                25.18         38.54        3.5363    1   1   0
                25.64        100.00        3.4733    1   1   1
                26.99         58.72        3.3026    1   1   2
                27.28         42.22        3.2689    1   0   4
                28.99         18.99        3.0794    0   0   6
                29.11         88.93        3.0667    1   1   3
                31.86         36.22        2.8079    1   1   4
                32.65          3.84        2.7420    0   2   0
                34.10         17.79        2.6286    0   2   2
                34.99         28.12        2.5635    1   0   6
                35.11         77.25        2.5549    1   1   5
                37.81          6.24        2.3783    0   1   7
                38.14         16.30        2.3589    1   2   0
                38.15         27.97        2.3578    0   2   4
                38.46         15.17        2.3399    1   2   1
                38.76         15.22        2.3223    1   1   6
                38.91          3.17        2.3134    2   0   0
                38.98         10.31        2.3095    0   0   8
                40.95          7.19        2.2028    1   2   3
                42.68          2.60        2.1175    2   1   1
                42.73          4.39        2.1152    1   1   7
                43.74         15.99        2.0685    2   0   4
                43.79          5.70        2.0664    1   0   8
                44.21          9.52        2.0478    0   2   6
                44.98          1.65        2.0143    2   1   3
                45.60          2.73        1.9883    1   2   5
                46.92         11.05        1.9354    2   1   4
                46.97         14.12        1.9337    1   1   8
                47.25          2.66        1.9226    0   1   9
                49.33         10.79        1.8464    2   1   5
                49.30          2.23        1.8476    0   0  10
                51.44         15.33        1.7754    1   1   9
                51.67         47.81        1.7682    2   2   0
                51.72          4.56        1.7664    0   2   8
                51.96          2.92        1.7588    1   2   7
                52.16          8.30        1.7526    2   1   6
                52.17          3.87        1.7524    0   3   3
                53.37          3.40        1.7159    1   0  10
                53.90         10.71        1.7001    1   3   0
                54.15          5.12        1.6930    1   3   1
                54.88          1.36        1.6720    1   3   2
                55.37         24.43        1.6583    2   1   7
                55.67          1.87        1.6502    1   2   8
                56.09          6.54        1.6388    1   3   3
                56.13          1.17        1.6376    1   1  10
                56.10          3.18        1.6385    0   3   5
                56.25          5.86        1.6345    2   0   8
                57.75          2.03        1.5955    1   3   4
                58.93          7.23        1.5664    2   1   8
                59.85         22.52        1.5445    1   3   5
                60.06          6.94        1.5397    0   0  12
                60.33          7.23        1.5334    2   2   6
                60.38         11.19        1.5322    0   2  10
                61.69          9.36        1.5028    0   3   7
                62.35          1.21        1.4883    1   3   6
                62.75          3.85        1.4799    3   1   1
                63.66          4.20        1.4609    1   0  12
                63.97          5.21        1.4545    1   2  10
                64.53          5.75        1.4433    3   1   3
                64.51          6.78        1.4437    2   0  10
                65.24          1.86        1.4293    1   3   7
                66.06          2.43        1.4135    3   1   4
                66.16          4.03        1.4117    1   1  12
                66.57         17.58        1.4039    2   2   8
                68.01         13.48        1.3776    3   1   5
                68.45          2.09        1.3698    2   3   4
                68.38          7.33        1.3710    0   4   0
                68.71          1.37        1.3652    0   3   9
                69.94          2.64        1.3442    3   2   0
                70.15          1.89        1.3407    3   2   1
                70.04          3.39        1.3425    0   2  12
                71.46          1.10        1.3193    2   1  11
                71.50          2.97        1.3187    1   1  13
                71.76          1.19        1.3145    1   4   0
                72.09          6.55        1.3094    1   3   9
                72.68          2.19        1.3002    2   3   6
                73.08          1.04        1.2940    3   1   7
                73.30          6.70        1.2907    3   2   4
                73.39          5.74        1.2893    1   2  12
                73.84          1.82        1.2826    3   0   8
                73.64          1.15        1.2855    1   4   3
                73.89          2.04        1.2818    2   0  12
                74.19          3.49        1.2774    2   2  10
                75.09          2.22        1.2643    1   4   4
                76.18          3.09        1.2489    3   1   8
                77.09          3.41        1.2364    1   1  14
                77.42          4.62        1.2320    3   2   6
                78.44          1.83        1.2184    2   3   8
                78.52          1.17        1.2174    1   2  13
                79.18          2.06        1.2090    1   4   6
                79.64          3.82        1.2030    3   1   9
                79.74          3.75        1.2018    0   1  15
                81.19          1.85        1.1840    3   0  10
                81.57          5.25        1.1794    2   4   0
                81.82          3.53        1.1764    3   3   1
                81.61          6.51        1.1789    0   4   8
                82.37          3.39        1.1699    2   4   2
                83.08          2.53        1.1618    3   2   8
                82.95          3.87        1.1632    1   1  15
                83.13          1.41        1.1612    2   2  12
                83.52          3.00        1.1567    4   0   0
                83.43          3.30        1.1578    3   3   3
                84.32          1.40        1.1477    4   0   2
                84.78          5.37        1.1428    2   4   4
                84.92          3.54        1.1412    1   3  12
                86.63          3.73        1.1230    3   3   5
                88.99          1.67        1.0993    4   1   4
                88.82          1.01        1.1009    3   3   6
                88.77          1.20        1.1014    2   4   6
                89.90          2.19        1.0904    1   3  13
                89.90          2.19        1.0904    1   3  13
       XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs
  For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.