Tveitite-(Y)
Diffraction data computed using the structure from the paper listed below,
along with the cell parameters refined from the powder pattern for R060895
      Bevan D J M, Strahle J, Greis O
      Journal of Solid State Chemistry 44 (1982) 75-81
      The crystal structure of tveitite, an ordered yttrofluorite mineral
      Note: a and b adjusted to match reported bond lengths

      CELL PARAMETERS:   16.96200   16.96200   9.666400   90.00000   90.00000   120.0000
      SPACE GROUP: R-3
      X-RAY WAVELENGTH:     1.541838
               2-THETA      INTENSITY    D-SPACING   H   K   L
                10.43         10.89        8.4977    1   1   0
                10.96         10.38        8.0890    1   0   1
                18.09          8.37        4.9061    3   0   0
                18.41          9.03        4.8236    2   1   1
                19.31          7.78        4.5988    0   1   2
                20.92          6.01        4.2488    2   2   0
                21.99          1.74        4.0445    2   0   2
                23.66          2.07        3.7615    1   3   1
                23.66          3.12        3.7615   -1   4   1
                24.38          3.06        3.6520   -1   3   2
                27.64         34.44        3.2275    0   0   3
                27.99          4.20        3.1883    5  -2   1
                27.99         95.80        3.1883    3   2   1
                28.61          4.42        3.1208    4  -1   2
                29.61          1.09        3.0172    2  -1   3
                30.52          2.63        2.9295    0   4   2
                32.33         20.80        2.7695   -2   5   2
                33.52          1.79        2.6734   -2   6   1
                34.91          2.26        2.5701    4  -2   3
                37.28          3.40        2.4118    6  -2   2
                37.28          1.15        2.4118    4   2   2
                38.34          1.69        2.3475    4   3   1
                38.81          2.23        2.3201   -1   6   2
                39.58          1.32        2.2766   -1   5   3
                40.64          1.03        2.2196    2   1   4
                41.72          1.42        2.1644    3   4   2
                41.72          4.56        2.1644   -3   7   2
                42.45          3.76        2.1289    6  -3   3
                43.45          1.41        2.0821   -1   4   4
                44.06          2.40        2.0547    3   5   1
                44.48          2.69        2.0363    7  -1   2
                44.81          1.04        2.0223    4   0   4
                45.40          2.58        1.9972    6   2   1
                46.13          1.60        1.9673    5  -2   4
                46.13         59.94        1.9673    3   2   4
                46.49          1.07        1.9530    0   6   3
                46.49          1.25        1.9530    6   0   3
                46.58         62.83        1.9495    1   7   0
                47.11          2.89        1.9286    0   7   2
                47.11          1.00        1.9286    8  -3   2
                47.11          3.25        1.9286    5   3   2
                47.34          3.86        1.9199    0   1   5
                48.69          1.25        1.8697    0   5   4
                49.25          2.63        1.8498    5   4   1
                49.25          1.20        1.8498    9  -4   1
                52.06          1.02        1.7561    4   5   2
                52.27          1.25        1.7496    4  -1   5
                53.25          1.14        1.7198    8   0   2
                53.45          1.08        1.7137    0   4   5
                54.62         16.36        1.6798   -2   5   5
                55.01         14.74        1.6687    8  -1   3
                55.01         14.48        1.6687    1   7   3
                55.21         13.71        1.6632   -4  10   1
                57.82          2.64        1.5942    6   4   2
                61.44          1.56        1.5086    2   2   6
                62.43          1.25        1.4870    5   4   4
                63.41          1.04        1.4662    7  -1   5
                65.50          1.09        1.4244    0   7   5
                67.62         12.69        1.3848   -4  10   4
                74.03          4.18        1.2800    3   2   7
                74.53          4.99        1.2726    6   4   5
                75.03          4.21        1.2653    4   9   1
                75.03          4.06        1.2653   11   1   1
                85.11          6.10        1.1393   -2   5   8
                86.08          5.42        1.1289    4   9   4
                86.08          5.56        1.1289   11   1   4
                86.40          1.94        1.1255    9   6   0
                86.40          1.94        1.1255    9   6   0
       XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs
  For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.