Gaspeite
Diffraction data computed using the structure from the paper listed below, 
along with the cell parameters refined from the powder pattern of R040157
      Graf D L
      American Mineralogist 46 (1961) 1283-1316
      Crystallographic tables for the rhombohedral carbonates

      CELL PARAMETERS:   4.6223  4.6223 14.9150   90.000   90.000  120.000
      SPACE GROUP: R-3c      

           ATOM        X         Y         Z     OCCUPANCY  ISO(B)
            Ni     0.00000   0.00000   0.00000     1.000     0.700
            C      0.00000   0.00000   0.25000     1.000     0.300
            O      0.27970   0.00000   0.25000     1.000     1.000

            X-RAY WAVELENGTH:     1.541838
            BOUNDS ON TWO THETA:    5.0  90.0
            LIMITS IMPOSED ON THE INDICES ARE:  +/-  3 +/-  3 +/- 13
            MAX. ABS. INTENSITY / VOLUME**2:      55.23458424    
            The INTENSITY cut off value is   1.00

               2-THETA      INTENSITY    D-SPACING   H   K   L
                25.25         47.74        3.5270    0   1   2
                32.82        100.00        2.7284    1   0   4
                38.97         24.11        2.3112    1   1   0
                43.17         15.06        2.0958    1   1   3
                47.01         20.94        1.9331    2   0   2
                51.84         12.41        1.7635    0   2   4
                54.19         30.55        1.6926    1   1   6
                54.28         18.95        1.6901    0   1   8
                61.61          1.31        1.5053    2   1   1
                62.65         13.59        1.4828    1   2   2
                66.72         11.63        1.4020    2   1   4
                66.95          3.07        1.3976    1   0  10
                68.82          4.69        1.3642    2   0   8
                69.84          1.88        1.3468    1   1   9
                70.59         10.65        1.3343    3   0   0
                76.67          3.25        1.2429    0   0  12
                80.27          3.07        1.1960    0   2  10
                82.02          5.85        1.1748    1   2   8
                89.54          3.56        1.0947    1   1  12
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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.