Pyroxene-ideal
      Thompson R M, Downs R T
      American Mineralogist 89 (2004) 614-628
      Model pyroxenes II: Structural variation as a function of tetrahedral rotation
      model with O3-O3-O3 angle = 160 and model oxygen radius = 1
      Note: Atoms Mg, Si, and O are assigned to atomic positions for convenience
      _database_code_amcsd 0003475

      CELL PARAMETERS:    7.3260   6.8230   3.9390   90.000  107.700   90.000
      SPACE GROUP: C2/c      
      X-RAY WAVELENGTH:     1.541838
      Cell Volume:    187.572
      Density (g/cm3):      7.109
      MAX. ABS. INTENSITY / VOLUME**2:      12.56353513    
      RIR:      0.575
      RIR based on corundum from Acta Crystallographica A38 (1982) 733-739
               2-THETA      INTENSITY    D-SPACING   H   K   L   Multiplicity
                26.12         36.50        3.4115    0   2   0         2
                33.06          4.78        2.7092    1   1   1         4
                35.56         81.62        2.5243    0   2   1         4
                36.85         33.89        2.4394    2   2   0         4
                39.55        100.00        2.2785   -2   2   1         4
                40.99         93.95        2.2019    3   1   0         4
                41.13         49.62        2.1947   -3   1   1         4
                41.77          6.29        2.1624    1   3   0         4
                46.45         65.97        1.9550   -1   3   1         4
                47.54         10.90        1.9128   -2   0   2         2
                48.12          2.17        1.8911   -1   1   2         4
                48.52         61.26        1.8763    0   0   2         2
                48.65         34.34        1.8716    2   2   1         4
                50.67          1.01        1.8016    1   3   1         4
                52.44          2.97        1.7448    4   0   0         2
                53.74          1.65        1.7057    0   4   0         2
                54.01         17.71        1.6978    3   1   1         4
                54.35          2.80        1.6879   -3   1   2         4
                55.04          1.79        1.6684   -2   2   2         4
                55.93          1.58        1.6440    0   2   2         4
                56.14         13.35        1.6384    1   1   2         4
                56.59          2.57        1.6263    3   3   0         4
                56.70         25.29        1.6234   -3   3   1         4
                57.76          7.23        1.5961   -4   2   1         4
                59.51          2.64        1.5534    4   2   0         4
                59.53         13.91        1.5528    0   4   1         4
                60.40          5.23        1.5325    2   4   0         4
                60.48         15.28        1.5307   -4   0   2         2
                62.31         17.70        1.4901   -2   4   1         4
                62.98          6.69        1.4759    2   0   2         2
                67.01          1.20        1.3966   -4   2   2         4
                67.76          1.44        1.3830   -3   3   2         4
                68.63          2.46        1.3675    5   1   0         4
                69.25         13.61        1.3567    2   4   1         4
                69.33          1.02        1.3554    1   3   2         4
                69.38          6.94        1.3546    2   2   2         4
                70.29          2.63        1.3392    1   5   0         4
                71.78          4.22        1.3150    4   2   1         4
                72.38          1.91        1.3056   -5   1   2         4
                74.54          2.52        1.2731   -2   4   2         4
                75.30          2.51        1.2621    0   4   2         4
                75.43          8.82        1.2603    3   1   2         4
                75.91          4.79        1.2535   -3   1   3         4
                76.88          2.46        1.2400   -4   4   1         4
                77.66         21.86        1.2295   -5   3   1         4
                78.10         18.87        1.2236   -2   2   3         4
                81.83          3.18        1.1771    3   5   0         4
                81.93          3.43        1.1759   -3   5   1         4
                82.06          1.35        1.1744    0   2   3         4
                83.02         10.45        1.1632    6   0   0         2
                83.39         12.14        1.1589   -6   0   2         2
                85.36         17.53        1.1372    0   6   0         2
                86.05         13.81        1.1299   -1   3   3         4
                87.07          1.69        1.1192    4   0   2         2
                87.37          2.73        1.1161    2   4   2         4
                88.93          1.61        1.1006   -5   1   3         4
                89.64          1.79        1.0937    4   4   1         4
================================================================================
       XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs
  For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.