Akermanite
      Kusaka K, Hagiya K, Ohmasa M, Okano Y, Mukai M, Iishi K, Haga N
      Physics and Chemistry of Minerals 28 (2001) 150-166
      Determination of structures of Ca2CoSi2O7, Ca2MgSi2O7, and Ca2(Mg.55Fe.45)Si2O7
      in incommensurate and normal phases and observation of diffuse streaks at high temperature
      Sample: T = 297 K
      Melilite group
      _database_code_amcsd 0008517

      CELL PARAMETERS:    7.8348   7.8348   5.0087   90.000   90.000   90.000
      SPACE GROUP: P-42_1m   
      X-RAY WAVELENGTH:     1.541838
      Cell Volume:    307.454
      Density (g/cm3):      2.944
      MAX. ABS. INTENSITY / VOLUME**2:      22.39738092    
      RIR:      2.477
      RIR based on corundum from Acta Crystallographica A38 (1982) 733-739
               2-THETA      INTENSITY    D-SPACING   H   K   L   Multiplicity
                16.00          9.72        5.5400    1   1   0         4
                17.71          1.84        5.0087    0   0   1         2
                21.05          6.96        4.2200    1   0   1         8
                22.70          3.26        3.9174    2   0   0         4
                23.95         11.26        3.7154    1   1   1         4
                25.42          4.23        3.5038    2   1   0         8
                28.94         23.35        3.0857    2   0   1         8
                31.15        100.00        2.8711    2   1   1         8
                32.32          3.92        2.7700    2   2   0         4
                35.86          1.79        2.5043    0   0   2         2
                36.26         16.49        2.4776    3   1   0         8
                37.09          5.27        2.4240    2   2   1         4
                37.71          6.52        2.3854    1   0   2         8
                38.89          6.61        2.3157    3   0   1         8
                39.49          2.63        2.2820    1   1   2         4
                40.63          1.47        2.2207    3   1   1         8
                44.47         12.72        2.0374    2   1   2         8
                45.50          2.20        1.9935    3   2   1         8
                46.36          5.70        1.9587    4   0   0         4
                47.87          6.55        1.9002    4   1   0         8
                49.04          4.10        1.8577    2   2   2         4
                49.35          9.72        1.8467    3   3   0         4
                51.43          9.22        1.7767    4   1   1         8
                51.91         19.26        1.7613    3   1   2         8
                52.21          6.07        1.7519    4   2   0         8
                52.84          3.32        1.7327    3   3   1         4
                55.00          1.06        1.6696    0   0   3         2
                56.03          2.39        1.6413    3   2   2         8
                57.67          1.78        1.5986    1   1   3         4
                60.26          1.53        1.5359    2   0   3         8
                61.23          1.02        1.5138    4   1   2         8
                61.53          4.48        1.5072    2   1   3         8
                62.49          1.35        1.4863    3   3   2         4
                63.31          2.81        1.4690    5   1   1         8
                65.25          4.66        1.4299    2   2   3         4
                66.47          2.48        1.4067    3   0   3         8
                66.98          8.97        1.3971    5   2   1         8
                67.64          2.91        1.3850    4   4   0         4
                70.55          1.72        1.3349    4   4   1         4
                70.95          1.38        1.3284    4   3   2         8
                72.37          3.16        1.3058    6   0   0         4
                73.53          1.15        1.2880    6   1   0         8
                75.59          1.15        1.2580    5   2   2         8
                75.85          4.39        1.2542    4   1   3         8
                76.00          1.16        1.2522    0   0   4         2
                77.00          2.12        1.2385    3   3   3         4
                79.74          1.95        1.2026    6   2   1         8
                80.87          2.30        1.1886    5   4   1         8
                81.25          1.28        1.1840    5   3   2         8
                83.49          2.06        1.1579    6   0   2         8
                84.87          1.48        1.1426    4   3   3         8
                85.01          1.02        1.1410    2   2   4         4
                85.98          2.46        1.1306    5   1   3         8
                86.12          1.28        1.1291    3   0   4         8
                87.23          1.28        1.1176    3   1   4         8
                87.94          1.05        1.1104    6   2   2         8
                89.31          1.21        1.0969    5   2   3         8
================================================================================
       XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs
  For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.