Zircon
Diffraction data computed using the structure from the paper listed below, 
along with the cell parameters refined from the powder pattern of R050034
      Hazen R M, Finger L W
      American Mineralogist 64 (1979) 196-201
      Crystal structure and compressibility of zircon at high pressure
      crystal No. 1, 1 atm - before P

      CELL PARAMETERS:   6.6077  6.6077  5.9957   90.000   90.000   90.000
      ALTERNATE SETTING FOR SPACE GROUP: I4_1/amd  

           ATOM        X         Y         Z     OCCUPANCY  ISO(B)
            Zr     0.00000   0.75000   0.12500     1.000     0.276
            Si     0.00000   0.25000   0.37500     1.000     0.311
            O      0.00000   0.06600   0.19510     1.000     0.503

            X-RAY WAVELENGTH:     1.541838
            BOUNDS ON TWO THETA:    5.0  90.0
            LIMITS IMPOSED ON THE INDICES ARE:  +/-  6 +/-  6 +/-  5
            MAX. ABS. INTENSITY / VOLUME**2:      73.65179765    
            The INTENSITY cut off value is   1.00

               2-THETA      INTENSITY    D-SPACING   H   K   L
                20.00         42.61        4.4402    1   0   1
                26.99        100.00        3.3038    2   0   0
                33.82          7.57        2.6506    2   1   1
                35.58         58.08        2.5232    1   1   2
                38.54         12.84        2.3362    2   2   0
                40.64          6.07        2.2201    2   0   2
                43.79         20.35        2.0675    3   0   1
                47.53         13.63        1.9130    1   0   3
                52.19         14.22        1.7526    3   2   1
                53.45         54.07        1.7142    3   1   2
                55.51          3.55        1.6555    2   1   3
                55.64         14.85        1.6519    4   0   0
                59.73          2.73        1.5482    4   1   1
                61.90          3.08        1.4989    0   0   4
                62.78          2.91        1.4801    3   0   3
                62.90          9.75        1.4775    4   2   0
                67.81         16.91        1.3821    3   3   2
                68.77         10.22        1.3650    2   0   4
                73.36          5.10        1.2906    4   3   1
                75.33          8.79        1.2616    2   2   4
                76.14          2.51        1.2503    4   1   3
                80.80          9.59        1.1895    5   1   2
                82.60          2.93        1.1681    4   4   0
                87.86          2.56        1.1111    2   1   5
                87.97          5.10        1.1101    4   0   4
                88.75          1.96        1.1023    5   0   3
                88.86          4.57        1.1013    6   0   0
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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.