Magnesite
Diffraction data computed using the structure from the paper listed below,
along with the cell parameters refined from the powder pattern for R050676
      Graf D L
      American Mineralogist 46 (1961) 1283-1316
      Crystallographic tables for the rhombohedral carbonates

      CELL PARAMETERS:   4.641546   4.641546   15.07108   90.00000   90.00000   120.0000
      SPACE GROUP: R-3c
      X-RAY WAVELENGTH:     1.541838
               2-THETA      INTENSITY    D-SPACING   H   K   L
                32.54        100.00        2.7490    1   0   4
                35.72         13.07        2.5118    0   0   6
                38.77          6.30        2.3208    1   1   0
                42.89         49.05        2.1068    1   1   3
                46.74         12.62        1.9420    2   0   2
                51.49          5.33        1.7733    0   2   4
                53.69         17.79        1.7058    0   1   8
                53.73         22.11        1.7046    1   1   6
                61.27          4.62        1.5116    2   1   1
                62.29          6.85        1.4893    1   2   2
                66.28          6.14        1.4091    2   1   4
                68.17          2.13        1.3745    2   0   8
                69.11          6.22        1.3580    1   1   9
                69.19          2.67        1.3567    1   2   5
                70.18         12.40        1.3399    3   0   0
                75.66          4.46        1.2559    0   0  12
                76.71          1.70        1.2413    2   1   7
                79.41          1.69        1.2058    0   2  10
                81.28          3.13        1.1826    1   2   8
                88.43          1.28        1.1046    1   1  12
                88.43          1.28        1.1046    1   1  12
       XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs
  For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.