Titanite
Diffraction data computed using the structure from the paper listed below, 
along with the cell parameters refined from the powder pattern of R050124
      Speer J A, Gibbs G V
      American Mineralogist 61 (1976) 238-247
      The crystal structure of synthetic titanite, CaTiOSiO4, and the domain textures
      of natural titanites

      CELL PARAMETERS:   7.0648  8.6977  6.5538   90.000  113.928   90.000
      SPACE GROUP: P2_1/a    

           ATOM        X         Y         Z     OCCUPANCY  ISO(B)
            Ca     0.24240   0.91840   0.75120     1.000     1.015
            Ti     0.51340   0.75420   0.24950     1.000     0.420
            Si     0.74860   0.93300   0.74900     1.000     0.253
            O      0.74990   0.82020   0.25020     1.000     0.687
            O      0.91080   0.81620   0.93470     1.000     0.746
            O      0.38270   0.96080   0.14590     1.000     0.679
            O      0.91220   0.31650   0.43680     1.000     0.690
            O      0.38130   0.46010   0.64680     1.000     0.580

            X-RAY WAVELENGTH:     1.541838
            BOUNDS ON TWO THETA:    5.0  90.0
            LIMITS IMPOSED ON THE INDICES ARE:  +/-  5 +/-  7 +/-  5
            MAX. ABS. INTENSITY / VOLUME**2:      16.45049579    
            The INTENSITY cut off value is   1.00

               2-THETA      INTENSITY    D-SPACING   H   K   L
                17.98         23.10        4.9336    0   1   1
                20.42          1.31        4.3488    0   2   0
                27.50        100.00        3.2433   -2   1   1
                27.63          3.17        3.2288    2   0   0
                29.51          1.05        3.0270    2   1   0
                29.83         72.27        2.9953    0   0   2
                31.44          6.60        2.8455   -2   0   2
                34.31          1.27        2.6137   -1   2   2
                34.36         63.82        2.6097    0   3   1
                34.60         45.85        2.5924    2   2   0
                37.78          3.86        2.3811   -2   2   2
                38.07          4.44        2.3640    2   1   1
                39.46         17.89        2.2835    1   3   1
                39.70         10.98        2.2704   -3   1   1
                40.42          4.60        2.2315   -2   3   1
                41.53          2.44        2.1744    0   4   0
                42.91          9.92        2.1078   -1   1   3
                43.42          4.38        2.0840    1   2   2
                43.80         17.16        2.0667   -2   1   3
                43.94         10.05        2.0607    1   4   0
                45.76          2.07        1.9828   -3   2   2
                46.67          7.04        1.9462    0   1   3
                48.58          1.26        1.8742    2   3   1
                49.17          3.33        1.8529    2   0   2
                50.61          9.86        1.8036    2   4   0
                51.69          1.29        1.7683    3   1   1
                51.97          1.45        1.7596    0   4   2
                52.35         12.65        1.7477   -4   0   2
                53.00         13.20        1.7277   -2   4   2
                53.41          2.83        1.7153   -2   3   3
                53.50          3.56        1.7127   -4   1   1
                53.78         18.57        1.7047    2   2   2
                55.22          1.41        1.6636   -1   5   1
                55.91         24.93        1.6445    0   3   3
                57.05          4.39        1.6144    4   0   0
                59.34         13.75        1.5573   -2   5   1
                60.49          7.33        1.5305   -2   2   4
                61.96          5.37        1.4976    0   0   4
                62.02         17.72        1.4963   -4   3   1
                62.79          1.13        1.4798    1   3   3
                64.26          2.39        1.4496    0   6   0
                65.00          4.88        1.4348    2   1   3
                65.62         11.77        1.4227   -4   0   4
                65.78          7.97        1.4196    2   5   1
                66.20          7.35        1.4117   -4   3   3
                66.27          2.35        1.4103    2   4   2
                69.84          9.44        1.3467   -2   5   3
                72.30          3.03        1.3069   -2   4   4
                72.43          7.10        1.3048    0   6   2
                73.05          1.19        1.2952   -2   1   5
                74.35          8.20        1.2758    4   3   1
                77.76          4.33        1.2282    4   0   2
                78.76          1.10        1.2151   -3   6   2
                80.99          1.02        1.1872    2   0   4
                81.50          1.22        1.1811   -3   3   5
                84.62          2.08        1.1453    2   2   4
                85.82          3.34        1.1323   -4   3   5
                87.39          1.62        1.1159    2   5   3
                87.41          1.57        1.1158   -4  -6   2
                88.10          3.25        1.1088    2   7   1
                88.25          5.03        1.1073    0   3   5
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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.