Vivianite
Diffraction data computed using the structure from the paper listed below,
along with the cell parameters refined from the powder pattern for R050596
      Takagi S, Mathew M, Brown W E
      American Mineralogist 71 (1986) 1229-1233
      Crystal structures of bobierrite and synthetic Mg3(PO4)2.8H2O

      CELL PARAMETERS:   10.09577   13.34555   4.674869   90.00000   104.6410   90.00000
      SPACE GROUP: C2/m
      X-RAY WAVELENGTH:     1.541838
               2-THETA      INTENSITY    D-SPACING   H   K   L
                11.20         32.88        7.8822    1   1   0
                13.24        100.00        6.6728    0   2   0
                18.13          4.75        4.8840    2   0   0
                20.52         13.14        4.3220   -1   1   1
                21.92          1.63        4.0484    1   3   0
                22.53          4.05        3.9411    2   2   0
                23.14          8.60        3.8371   -2   0   1
                23.73          1.43        3.7440    0   2   1
                24.57          3.27        3.6175    1   1   1
                26.68          1.74        3.3364    0   4   0
                27.96         19.07        3.1871   -1   3   1
                28.17          6.93        3.1632    3   1   0
                30.20         17.83        2.9553   -3   1   1
                30.09         13.85        2.9658    2   0   1
                32.46          3.26        2.7549    2   4   0
                33.01         18.72        2.7102    2   2   1
                33.33         17.15        2.6850    0   4   1
                34.08          4.48        2.6274    3   3   0
                35.61         24.22        2.5177   -2   4   1
                35.81          1.83        2.5046   -3   3   1
                36.76          5.50        2.4420    4   0   0
                37.11          9.30        2.4196   -4   0   1
                38.48          1.09        2.3367    3   1   1
                39.04          2.80        2.3046   -1   5   1
                39.08          2.41        2.3018   -1   1   2
                39.57          2.09        2.2747   -4   2   1
                39.81          3.30        2.2615    0   0   2
                40.65         11.63        2.2166    2   4   1
                41.44          4.15        2.1761    1   5   1
                41.75          1.52        2.1610   -2   2   2
                43.03          1.24        2.0998   -3   1   2
                43.81          2.94        2.0642    3   5   0
                43.79          3.18        2.0650    1   1   2
                45.39          2.67        1.9960    0   6   1
                46.30          2.85        1.9588   -4   4   1
                46.17          2.60        1.9638   -5   1   1
                47.18          3.29        1.9243   -2   6   1
                46.95          1.63        1.9330    5   1   0
                47.33          3.10        1.9184   -3   3   2
                47.33          3.65        1.9186   -4   0   2
                48.04          4.67        1.8918    1   3   2
                48.60          1.14        1.8712    1   7   0
                48.38          2.20        1.8791    2   0   2
                50.27          1.49        1.8130   -5   3   1
                51.47          1.88        1.7736    3   5   1
                51.91          1.06        1.7594   -1   7   1
                51.95          1.17        1.7582   -1   5   2
                54.98          5.42        1.6682    0   8   0
                55.17          5.63        1.6631   -3   5   2
                55.80          5.53        1.6457    1   5   2
                56.11          1.09        1.6373    2   4   2
                56.17          1.02        1.6358    5   1   1
                57.82          3.12        1.5930   -5   5   1
                58.48          3.41        1.5764    5   5   0
                58.27          2.87        1.5816    6   2   0
                59.77          1.86        1.5455    5   3   1
                61.09          2.96        1.5153   -6   0   2
                62.01          3.56        1.4951   -6   4   1
                62.84          1.52        1.4773   -1   7   2
                62.57          4.33        1.4829    4   0   2
                63.48          1.77        1.4639   -1   3   3
                63.96          1.82        1.4540    2   8   1
                65.27          1.14        1.4281    1   1   3
                66.21          2.45        1.4100   -2   4   3
                68.18          1.32        1.3739    0   4   3
                70.49          2.97        1.3346    0  10   0
                70.13          2.65        1.3406   -1   5   3
                70.65          2.29        1.3319   -3   9   1
                70.36          1.14        1.3367   -6   6   1
                71.22          1.33        1.3226   -3   5   3
                76.64          1.87        1.2421    7   1   1
                77.04          1.86        1.2366    7   5   0
                78.52          1.39        1.2170    2  10   1
                82.47          1.43        1.1684   -2   0   4
                86.73          1.24        1.1216   -6   8   2
                88.04          1.19        1.1083    4   8   2
                88.04          1.19        1.1083    4   8   2
       XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs
  For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.