Akermanite
      Kusaka K, Ohmasa M, Hagiya K, Iishi K, Haga N
      Mineralogical Journal 20 (1998) 47-58
      On variety of the Ca coordination in the incommensurate structure of
      synthetic iron-bearing akermanite, Ca2(Mg0.55,Fe0.45)Si2O7
      Note: Sample is synthetic, this is the structure obtained by refining the incommensurate
      structure
      _database_code_amcsd 0014432

      CELL PARAMETERS:    7.8679   7.8679   5.0144   90.000   90.000   90.000
      SPACE GROUP: P-42_1m   
      X-RAY WAVELENGTH:     1.541838
      Cell Volume:    310.411
      Density (g/cm3):      3.067
      MAX. ABS. INTENSITY / VOLUME**2:      22.23877348    
      RIR:      2.361
      RIR based on corundum from Acta Crystallographica A38 (1982) 733-739
               2-THETA      INTENSITY    D-SPACING   H   K   L   Multiplicity
                15.93          2.54        5.5634    1   1   0         4
                17.69          5.89        5.0144    0   0   1         2
                21.01          6.95        4.2286    1   0   1         8
                23.89         17.73        3.7247    1   1   1         4
                25.31          4.33        3.5186    2   1   0         8
                28.85         37.22        3.0951    2   0   1         8
                31.05        100.00        2.8803    2   1   1         8
                32.18          6.51        2.7817    2   2   0         4
                35.82          3.30        2.5072    0   0   2         2
                36.10         23.65        2.4880    3   1   0         8
                36.95          6.04        2.4325    2   2   1         4
                37.65          6.58        2.3888    1   0   2         8
                38.75          6.97        2.3240    3   0   1         8
                39.42          2.61        2.2858    1   1   2         4
                40.47          2.58        2.2288    3   1   1         8
                44.36         12.24        2.0419    2   1   2         8
                45.32          2.05        2.0009    3   2   1         8
                46.15          3.59        1.9670    4   0   0         4
                47.66          7.50        1.9082    4   1   0         8
                48.91          6.77        1.8624    2   2   2         4
                49.13          7.90        1.8545    3   3   0         4
                51.22          9.25        1.7835    4   1   1         8
                51.76         24.72        1.7660    3   1   2         8
                51.98          8.11        1.7593    4   2   0         8
                52.62          5.14        1.7393    3   3   1         4
                55.34          2.18        1.6601    4   2   1         8
                55.85          2.66        1.6460    3   2   2         8
                57.58          2.30        1.6008    1   1   3         4
                60.15          2.51        1.5384    2   0   3         8
                61.02          1.01        1.5185    4   1   2         8
                61.41          4.90        1.5098    2   1   3         8
                63.03          4.83        1.4748    5   1   1         8
                64.73          1.91        1.4401    4   2   2         8
                65.11          4.55        1.4327    2   2   3         4
                66.31          2.33        1.4095    3   0   3         8
                66.68          8.74        1.4027    5   2   1         8
                67.32          3.49        1.3909    4   4   0         4
                67.51          1.45        1.3874    3   1   3         8
                69.69          1.37        1.3493    5   3   0         8
                70.23          2.52        1.3403    4   4   1         4
                70.68          1.36        1.3328    4   3   2         8
                72.02          3.55        1.3113    6   0   0         4
                73.17          1.22        1.2935    6   1   0         8
                75.28          1.00        1.2623    5   2   2         8
                75.63          4.66        1.2573    4   1   3         8
                75.90          1.47        1.2536    0   0   4         2
                76.77          2.76        1.2416    3   3   3         4
                78.67          1.12        1.2162    4   4   2         4
                79.36          3.00        1.2074    6   2   1         8
                80.48          2.24        1.1934    5   4   1         8
                80.91          1.90        1.1882    5   3   2         8
                83.13          2.77        1.1620    6   0   2         8
                84.58          1.40        1.1457    4   3   3         8
                84.83          1.20        1.1429    2   2   4         4
                85.68          2.96        1.1338    5   1   3         8
                85.94          1.23        1.1310    3   0   4         8
                87.04          2.03        1.1195    3   1   4         8
                88.99          1.32        1.1000    5   2   3         8
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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.