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 = 200 and model oxygen radius = 1
      Note: Atoms Mg, Si, and O are assigned to atomic positions for convenience
      _database_code_amcsd 0003473

      CELL PARAMETERS:    7.6080   6.8230   3.9390   90.000  113.400   90.000
      SPACE GROUP: C2/c      
      X-RAY WAVELENGTH:     1.541838
      Cell Volume:    187.654
      Density (g/cm3):      7.106
      MAX. ABS. INTENSITY / VOLUME**2:      23.51395113    
      RIR:      1.078
      RIR based on corundum from Acta Crystallographica A38 (1982) 733-739
               2-THETA      INTENSITY    D-SPACING   H   K   L   Multiplicity
                26.12         19.49        3.4115    0   2   0         2
                26.29          8.15        3.3895   -1   1   1         4
                34.74          8.82        2.5822    1   1   1         4
                36.20         25.09        2.4811    0   2   1         4
                36.84         18.10        2.4400    2   2   0         4
                38.35        100.00        2.3469   -2   2   1         4
                39.08         23.93        2.3051   -3   1   1         4
                40.97         50.22        2.2028    3   1   0         4
                41.77          3.36        2.1625    1   3   0         4
                46.19          1.39        1.9654   -1   3   1         4
                46.51          2.00        1.9527   -2   0   2         2
                48.62          2.45        1.8727   -1   1   2         4
                50.49         47.27        1.8075    0   0   2         2
                50.61          4.00        1.8036    2   2   1         4
                51.87          8.14        1.7627    1   3   1         4
                52.42          1.59        1.7456    4   0   0         2
                55.11         20.84        1.6666   -3   3   1         4
                56.50          7.20        1.6286    3   1   1         4
                56.58          1.37        1.6266    3   3   0         4
                56.95          6.45        1.6169   -4   0   2         2
                59.48          1.41        1.5540    4   2   0         4
                59.97          3.16        1.5426    0   4   1         4
                60.40          2.79        1.5326    2   4   0         4
                61.46         22.27        1.5087   -2   4   1         4
                67.11          3.75        1.3948    2   0   2         2
                68.60          1.31        1.3681    5   1   0         4
                69.66          1.25        1.3498    3   3   1         4
                70.29          1.40        1.3393    1   5   0         4
                70.84          1.05        1.3301    2   4   1         4
                73.33          2.53        1.2911    2   2   2         4
                73.52          1.14        1.2882   -1   5   1         4
                73.75          3.81        1.2846   -2   4   2         4
                74.50          4.18        1.2736    4   2   1         4
                75.12         21.66        1.2646   -5   3   1         4
                75.89          2.56        1.2537   -1   1   3         4
                78.04          1.87        1.2245   -6   0   2         2
                78.10         10.07        1.2237   -2   2   3         4
                80.40          7.78        1.1944    3   1   2         4
                80.59          1.59        1.1920   -3   5   1         4
                81.82          1.70        1.1772    3   5   0         4
                82.98          5.59        1.1637    6   0   0         2
                83.96          2.28        1.1525   -6   2   2         4
                85.36          9.36        1.1372    0   6   0         2
                86.05          7.38        1.1298   -3   3   3         4
                87.23          3.07        1.1176   -1   5   2         4
================================================================================
       XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs
  For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.