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 = 463 K
      Melilite group
      _database_code_amcsd 0008522

      CELL PARAMETERS:    7.8470   7.8470   5.0097   90.000   90.000   90.000
      SPACE GROUP: P-42_1m   
      X-RAY WAVELENGTH:     1.541838
      Cell Volume:    308.474
      Density (g/cm3):      2.935
      MAX. ABS. INTENSITY / VOLUME**2:      22.29736996    
      RIR:      2.474
      RIR based on corundum from Acta Crystallographica A38 (1982) 733-739
               2-THETA      INTENSITY    D-SPACING   H   K   L   Multiplicity
                15.97          9.63        5.5487    1   1   0         4
                17.70          1.71        5.0097    0   0   1         2
                21.04          7.34        4.2225    1   0   1         8
                22.66          3.22        3.9235    2   0   0         4
                23.93         11.49        3.7184    1   1   1         4
                25.38          4.20        3.5093    2   1   0         8
                28.90         23.25        3.0889    2   0   1         8
                31.12        100.00        2.8742    2   1   1         8
                32.27          3.96        2.7743    2   2   0         4
                35.85          1.64        2.5048    0   0   2         2
                36.20         16.16        2.4814    3   1   0         8
                37.04          5.50        2.4270    2   2   1         4
                37.70          6.51        2.3862    1   0   2         8
                38.84          6.62        2.3186    3   0   1         8
                39.47          2.79        2.2830    1   1   2         4
                40.57          1.59        2.2236    3   1   1         8
                44.44         13.08        2.0388    2   1   2         8
                45.44          2.37        1.9961    3   2   1         8
                46.28          5.83        1.9618    4   0   0         4
                47.79          6.71        1.9032    4   1   0         8
                48.99          4.10        1.8592    2   2   2         4
                49.27          9.83        1.8496    3   3   0         4
                51.36          9.25        1.7791    4   1   1         8
                51.86         19.73        1.7629    3   1   2         8
                52.13          6.22        1.7546    4   2   0         8
                52.76          3.35        1.7351    3   3   1         4
                54.99          1.15        1.6699    0   0   3         2
                55.97          2.45        1.6429    3   2   2         8
                57.65          1.74        1.5991    1   1   3         4
                60.23          1.51        1.5365    2   0   3         8
                61.50          4.37        1.5079    2   1   3         8
                62.41          1.35        1.4879    3   3   2         4
                63.21          2.75        1.4711    5   1   1         8
                65.21          4.74        1.4307    2   2   3         4
                66.42          2.66        1.4075    3   0   3         8
                66.87          9.12        1.3992    5   2   1         8
                67.52          2.97        1.3872    4   4   0         4
                70.43          1.75        1.3369    4   4   1         4
                70.85          1.42        1.3299    4   3   2         8
                72.24          3.22        1.3078    6   0   0         4
                73.40          1.15        1.2900    6   1   0         8
                75.48          1.28        1.2595    5   2   2         8
                75.78          4.48        1.2552    4   1   3         8
                75.98          1.17        1.2524    0   0   4         2
                76.21          1.06        1.2493    6   1   1         8
                76.92          2.22        1.2395    3   3   3         4
                79.60          2.00        1.2043    6   2   1         8
                80.72          2.37        1.1904    5   4   1         8
                81.13          1.27        1.1855    5   3   2         8
                83.36          2.05        1.1593    6   0   2         8
                84.77          1.53        1.1436    4   3   3         8
                84.96          1.06        1.1415    2   2   4         4
                85.88          2.45        1.1317    5   1   3         8
                86.07          1.28        1.1296    3   0   4         8
                87.18          1.18        1.1181    3   1   4         8
                87.80          1.13        1.1118    6   2   2         8
                89.20          1.16        1.0979    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.