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 = 413 K
      Melilite group
      _database_code_amcsd 0008521

      CELL PARAMETERS:    7.8436   7.8436   5.0070   90.000   90.000   90.000
      SPACE GROUP: P-42_1m   
      X-RAY WAVELENGTH:     1.541838
      Cell Volume:    308.041
      Density (g/cm3):      2.939
      MAX. ABS. INTENSITY / VOLUME**2:      22.43181476    
      RIR:      2.485
      RIR based on corundum from Acta Crystallographica A38 (1982) 733-739
               2-THETA      INTENSITY    D-SPACING   H   K   L   Multiplicity
                15.98          9.64        5.5463    1   1   0         4
                17.71          1.64        5.0070    0   0   1         2
                21.05          7.42        4.2204    1   0   1         8
                22.67          3.15        3.9218    2   0   0         4
                23.94         11.19        3.7166    1   1   1         4
                25.39          4.18        3.5078    2   1   0         8
                28.92         23.18        3.0875    2   0   1         8
                31.13        100.00        2.8729    2   1   1         8
                32.28          3.84        2.7731    2   2   0         4
                35.87          1.61        2.5035    0   0   2         2
                36.22         16.29        2.4804    3   1   0         8
                37.06          5.46        2.4259    2   2   1         4
                37.72          6.44        2.3850    1   0   2         8
                38.86          6.78        2.3176    3   0   1         8
                39.49          2.70        2.2818    1   1   2         4
                40.59          1.60        2.2226    3   1   1         8
                44.46         13.23        2.0377    2   1   2         8
                45.46          2.39        1.9952    3   2   1         8
                46.30          5.78        1.9609    4   0   0         4
                47.81          6.69        1.9024    4   1   0         8
                49.02          4.20        1.8583    2   2   2         4
                49.29         10.06        1.8488    3   3   0         4
                51.38          9.36        1.7783    4   1   1         8
                51.89         19.70        1.7620    3   1   2         8
                52.15          6.24        1.7539    4   2   0         8
                52.78          3.35        1.7343    3   3   1         4
                55.02          1.14        1.6690    0   0   3         2
                56.00          2.44        1.6421    3   2   2         8
                57.68          1.78        1.5982    1   1   3         4
                60.26          1.49        1.5357    2   0   3         8
                61.53          4.42        1.5071    2   1   3         8
                62.45          1.33        1.4872    3   3   2         4
                63.24          2.74        1.4704    5   1   1         8
                65.25          4.80        1.4300    2   2   3         4
                66.46          2.73        1.4068    3   0   3         8
                66.90          9.24        1.3985    5   2   1         8
                67.56          3.00        1.3866    4   4   0         4
                70.47          1.76        1.3363    4   4   1         4
                70.89          1.44        1.3293    4   3   2         8
                72.27          3.27        1.3073    6   0   0         4
                73.43          1.11        1.2895    6   1   0         8
                75.52          1.34        1.2590    5   2   2         8
                75.83          4.47        1.2546    4   1   3         8
                76.03          1.20        1.2517    0   0   4         2
                76.25          1.07        1.2487    6   1   1         8
                76.97          2.29        1.2389    3   3   3         4
                79.64          2.01        1.2038    6   2   1         8
                80.77          2.42        1.1899    5   4   1         8
                81.17          1.27        1.1849    5   3   2         8
                83.41          2.09        1.1588    6   0   2         8
                84.82          1.56        1.1431    4   3   3         8
                85.02          1.04        1.1409    2   2   4         4
                85.93          2.52        1.1311    5   1   3         8
                86.13          1.30        1.1290    3   0   4         8
                87.24          1.21        1.1175    3   1   4         8
                87.85          1.14        1.1113    6   2   2         8
                89.26          1.20        1.0974    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.