Hematite
Diffraction data computed using the structure from the paper listed below, 
along with the cell parameters refined from the powder pattern of R040024
      Blake R L, Hessevick R E, Zoltai T, Finger L W
      American Mineralogist 51 (1966) 123-129
      Refinement of the hematite structure

      CELL PARAMETERS:   5.0329  5.0329 13.7430   90.000   90.000  120.000
      SPACE GROUP: R-3c      

           ATOM        X         Y         Z     OCCUPANCY  ISO(B)
            Fe     0.00000   0.00000   0.35530     1.000     0.478
            O      0.30590   0.00000   0.25000     1.000     0.484

            X-RAY WAVELENGTH:     1.541838
            BOUNDS ON TWO THETA:    5.0  90.0
            LIMITS IMPOSED ON THE INDICES ARE:  +/-  4 +/-  4 +/- 12
            MAX. ABS. INTENSITY / VOLUME**2:      58.94575008    
            The INTENSITY cut off value is   1.00

               2-THETA      INTENSITY    D-SPACING   H   K   L
                24.18         28.77        3.6806    0   1   2
                33.20        100.00        2.6982    1   0   4
                35.68         73.82        2.5164    1   1   0
                39.34          2.05        2.2905    0   0   6
                40.92         17.99        2.2056    1   1   3
                43.57          1.95        2.0773    2   0   2
                49.53         37.44        1.8403    0   2   4
                54.15         45.07        1.6939    1   1   6
                57.53          2.34        1.6020    1   2   2
                57.68          8.50        1.5982    0   1   8
                62.53         30.66        1.4855    2   1   4
                64.09         29.50        1.4529    3   0   0
                69.70          3.04        1.3491    2   0   8
                72.06         10.83        1.3107    1   0  10
                72.39          1.72        1.3055    1   1   9
                75.57          6.97        1.2582    2   2   0
                77.86          1.26        1.2269    0   3   6
                77.86          1.26        1.2269    3   0   6
                80.71          1.58        1.1906    3   1   2
                80.84          4.23        1.1890    1   2   8
                83.09          5.63        1.1625    0   2  10
                85.07          8.67        1.1403    1   3   4
                88.70          7.95        1.1028    2   2   6
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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.