Talc
Diffraction data computed using the structure from the paper listed below,
along with the cell parameters refined from the powder pattern for R040135
      Perdikatsis B, Burzlaff H
      Zeitschrift fur Kristallographie 156 (1981) 177-186
      Strukturverfeinerung am talk Mg3[(OH)2Si4O10]

      CELL PARAMETERS:   5.290000   9.173000   9.460000   90.46000   98.68000   90.09000
      SPACE GROUP: C-1
      X-RAY WAVELENGTH:     1.541838
               2-THETA      INTENSITY    D-SPACING   H   K   L
                 9.52        100.00        9.3487    0   0   1
                19.04         12.43        4.6744    0   0   2
                18.95         10.10        4.6959    0   2   0
                19.83         26.56        4.4890   -1   1   0
                18.59         27.13        4.7874    1   1   0
                19.91         19.20        4.4728   -1  -1   1
                21.34         26.81        4.1741    0  -2   1
                21.11          8.36        4.2187    0   2   1
                23.03         15.31        3.8703    1  -1   1
                25.11          1.21        3.5529   -1  -1   2
                25.87         15.38        3.4502   -1   1   2
                26.78         12.90        3.3350    0   2   2
                28.69         58.95        3.1162    0   0   3
                28.21          9.96        3.1690    1   1   2
                32.49          7.12        2.7593   -1  -1   3
                33.02          2.53        2.7164   -1   1   3
                34.34          2.27        2.6143   -1   3   0
                32.11          3.34        2.7914    1   3   0
                33.80          7.91        2.6554   -2   0   1
                33.72          7.26        2.6616    2   0   0
                32.99          9.18        2.7187   -1  -3   1
                34.96          9.53        2.5695   -1   3   1
                34.80          3.71        2.5808    0  -2   3
                36.43         30.44        2.4689    1  -3   1
                34.10         30.74        2.6328    1   3   1
                36.58         30.09        2.4591   -2   0   2
                37.07          4.07        2.4276    1  -1   3
                36.18          1.46        2.4855    1   1   3
                40.86         11.69        2.2104    1  -3   2
                38.56         10.51        2.3371    1   3   2
                41.60          7.38        2.1729   -2   0   3
                40.37          1.05        2.2364   -2  -2   2
                41.26          7.72        2.1900    2   0   2
                42.21          7.37        2.1425   -1  -3   3
                43.51          1.34        2.0814    0  -2   4
                43.47          6.90        2.0833   -1   3   3
                43.03          1.47        2.1035    0   2   4
                42.91          1.60        2.1094    0   4   2
                47.01          1.74        1.9342   -2   2   3
                47.09          2.46        1.9310    1  -3   3
                46.98          1.76        1.9352    2  -2   2
                44.87          2.43        2.0213    1   3   3
                48.28          2.88        1.8861   -2   0   4
                48.73          3.90        1.8697    0   0   5
                48.91          1.81        1.8634    0  -4   3
                52.91          1.32        1.7311   -1   5   0
                51.35          1.18        1.7802   -3  -1   1
                53.95          1.68        1.7001   -2   4   1
                50.69          1.77        1.8018    2   2   3
                50.02          1.02        1.8244   -2  -4   1
                53.28          1.51        1.7202   -3   1   0
                51.73          1.11        1.7679    3   1   0
                54.67          7.83        1.6794    1  -3   4
                54.36          1.21        1.6885   -3   1   2
                51.66          1.14        1.7704    1   5   1
                52.54          8.18        1.7425    1   3   4
                52.19          1.21        1.7536   -2  -4   2
                51.70          1.24        1.7689    2   4   1
                53.60          1.53        1.7106   -1  -5   2
                56.22          8.37        1.6367   -2   0   5
                58.45          1.31        1.5794   -1   3   5
                59.33          2.17        1.5581    0   0   6
                59.15          1.45        1.5624   -2  -2   5
                59.65          1.05        1.5505   -1   5   3
                58.18          1.01        1.5861    3   1   2
                59.03          9.59        1.5653    0   6   0
                61.60          9.06        1.5059   -3   3   1
                57.49          9.24        1.6036   -3  -3   1
                62.04          3.98        1.4963   -3   3   0
                57.80          3.46        1.5958    3   3   0
                60.08          2.55        1.5405    0  -6   1
                59.79          1.77        1.5471    0   6   1
                59.01          1.12        1.5657   -3  -3   2
                63.36          2.32        1.4683    1  -3   5
                61.28          1.85        1.5131    1   3   5
                63.17          1.26        1.4722    0   4   5
                64.66          8.78        1.4417    2   0   5
                67.06          8.95        1.3957   -1  -3   6
                67.59          8.72        1.3862   -1   3   6
                69.17          1.15        1.3582   -2   2   6
                69.13          1.12        1.3590    2  -2   5
                67.16          1.16        1.3939   -3  -3   4
                70.57          1.27        1.3347   -3   3   4
                70.52          2.02        1.3355    0   0   7
                72.28          2.38        1.3072   -2   6   0
                72.20          1.99        1.3084   -2   6   1
                67.25          1.04        1.3924   -2  -6   1
                67.07          2.43        1.3957    2   6   0
                71.00          1.36        1.3277   -4   0   2
                70.81          6.46        1.3308    4   0   0
                73.39          1.01        1.2901    3  -3   3
                69.11          5.23        1.3594   -2  -6   2
                73.75          4.34        1.2848   -2   6   2
                73.37          1.04        1.2904    0  -4   6
                73.54          2.09        1.2879   -4   0   3
                74.59          1.74        1.2723    2   0   6
                77.29          1.69        1.2345    2  -6   2
                71.70          1.23        1.3164    2   6   2
                81.56          1.18        1.1802   -2   6   4
                82.55          3.03        1.1686    4   0   3
                84.07          2.62        1.1512   -2  -6   5
                87.73          2.27        1.1123   -2   6   5
                87.73          2.27        1.1123   -2   6   5
       XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs
  For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.