Beryl
Diffraction data computed using the structure from the paper listed below, 
along with the cell parameters refined from the powder pattern of R050121
      Hazen R M, Au A Y, Finger L W
      American Mineralogist 71 (1986) 977-984
      High-pressure crystal chemistry of beryl (Be3Al2Si6O18) and euclase (BeAlSiO4OH)
      Sample: Pressure = .001 kbar

      CELL PARAMETERS:   9.2129  9.2129  9.1980   90.000   90.000  120.000
      SPACE GROUP: P6/mcc    

           ATOM        X         Y         Z     OCCUPANCY  ISO(B)
            Be     0.50000   0.00000   0.25000     1.000     0.570
            Al     0.33333   0.66667   0.25000     1.000     0.510
            Si     0.38760   0.11590   0.00000     1.000     0.440
            O      0.31030   0.23690   0.00000     1.000     0.820
            O      0.49850   0.14560   0.14530     1.000     0.680

            X-RAY WAVELENGTH:     1.541838
            BOUNDS ON TWO THETA:    5.0  90.0
            LIMITS IMPOSED ON THE INDICES ARE:  +/-  7 +/-  7 +/-  8
            MAX. ABS. INTENSITY / VOLUME**2:      18.42815372    
            The INTENSITY cut off value is   1.00

               2-THETA      INTENSITY    D-SPACING   H   K   L
                11.09        100.00        7.9786    1   0   0
                19.27          3.88        4.6065    1   1   0
                19.30         24.27        4.5990    0   0   2
                22.28          5.96        3.9893    2   0   0
                22.31         17.81        3.9845    1   0   2
                27.40         55.52        3.2546    1   1   2
                29.62          2.53        3.0156    2   1   0
                29.64         12.17        3.0135    2   0   2
                31.21         57.19        2.8656    2   1   1
                35.60         14.32        2.5218    2   1   2
                39.18          4.32        2.2995    0   0   4
                40.78          1.21        2.2129    3   1   0
                41.99          4.62        2.1515    3   1   1
                44.01          2.01        2.0574    1   1   4
                45.47          2.40        1.9947    4   0   0
                45.49          1.71        1.9940    3   1   2
                45.53          6.47        1.9922    2   0   4
                49.82          2.58        1.8304    3   2   0
                50.89          6.20        1.7943    3   1   3
                52.56          4.88        1.7411    4   1   0
                52.62          7.06        1.7395    3   0   4
                53.57          5.12        1.7107    4   1   1
                56.52          1.08        1.6283    4   1   2
                56.55          7.43        1.6273    2   2   4
                57.78          3.17        1.5957    5   0   0
                57.83          1.66        1.5945    3   1   4
                58.75          3.53        1.5716    3   2   3
                58.80          1.68        1.5705    2   1   5
                60.38          3.14        1.5330    0   0   6
                61.22          9.08        1.5140    4   1   3
                63.92          2.79        1.4565    3   3   2
                64.01          2.97        1.4546    1   1   6
                65.10          3.84        1.4328    4   2   2
                65.14          3.89        1.4321    3   2   4
                68.59          2.40        1.3681    5   1   2
                68.68          2.65        1.3666    2   1   6
                74.23          2.20        1.2776    5   2   0
                74.24          5.31        1.2774    6   0   2
                74.33          1.04        1.2762    2   2   6
                75.06          4.58        1.2655    5   2   1
                75.13          2.93        1.2645    4   1   5
                75.38          2.14        1.2609    4   2   4
                75.43          1.14        1.2602    3   1   6
                79.47          4.41        1.2060    4   3   3
                79.58          4.05        1.2046    2   1   7
                84.09          1.46        1.1511    6   0   4
                84.21          1.96        1.1497    0   0   8
                85.16          1.70        1.1393    4   3   4
                87.31          1.93        1.1168    5   2   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.