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 = 348 K
      Melilite group
      _database_code_amcsd 0008518

      CELL PARAMETERS:    7.8387   7.8387   5.0079   90.000   90.000   90.000
      SPACE GROUP: P-42_1m   
      X-RAY WAVELENGTH:     1.541838
      Cell Volume:    307.712
      Density (g/cm3):      2.942
      MAX. ABS. INTENSITY / VOLUME**2:      22.48543028    
      RIR:      2.489
      RIR based on corundum from Acta Crystallographica A38 (1982) 733-739
               2-THETA      INTENSITY    D-SPACING   H   K   L   Multiplicity
                15.99          9.61        5.5428    1   1   0         4
                17.71          1.77        5.0079    0   0   1         2
                21.05          7.07        4.2202    1   0   1         8
                22.69          3.20        3.9193    2   0   0         4
                23.95         11.30        3.7159    1   1   1         4
                25.41          4.17        3.5056    2   1   0         8
                28.93         23.25        3.0865    2   0   1         8
                31.14        100.00        2.8719    2   1   1         8
                32.30          3.91        2.7714    2   2   0         4
                35.86          1.72        2.5040    0   0   2         2
                36.24         16.34        2.4788    3   1   0         8
                37.07          5.40        2.4248    2   2   1         4
                37.71          6.50        2.3852    1   0   2         8
                38.88          6.67        2.3165    3   0   1         8
                39.49          2.67        2.2819    1   1   2         4
                40.61          1.53        2.2216    3   1   1         8
                44.46         12.93        2.0376    2   1   2         8
                45.48          2.29        1.9942    3   2   1         8
                46.33          5.79        1.9597    4   0   0         4
                47.84          6.66        1.9012    4   1   0         8
                49.03          4.13        1.8579    2   2   2         4
                49.32          9.86        1.8476    3   3   0         4
                51.41          9.31        1.7774    4   1   1         8
                51.90         19.59        1.7616    3   1   2         8
                52.19          6.16        1.7528    4   2   0         8
                52.81          3.35        1.7334    3   3   1         4
                55.01          1.11        1.6693    0   0   3         2
                56.02          2.43        1.6416    3   2   2         8
                57.67          1.78        1.5984    1   1   3         4
                60.26          1.52        1.5358    2   0   3         8
                61.53          4.49        1.5071    2   1   3         8
                62.47          1.37        1.4867    3   3   2         4
                63.28          2.80        1.4696    5   1   1         8
                65.25          4.76        1.4299    2   2   3         4
                66.46          2.58        1.4067    3   0   3         8
                66.95          9.18        1.3978    5   2   1         8
                67.61          2.97        1.3857    4   4   0         4
                70.51          1.76        1.3355    4   4   1         4
                70.93          1.42        1.3288    4   3   2         8
                72.33          3.24        1.3065    6   0   0         4
                73.49          1.15        1.2887    6   1   0         8
                75.56          1.25        1.2584    5   2   2         8
                75.84          4.49        1.2544    4   1   3         8
                76.01          1.19        1.2520    0   0   4         2
                76.30          1.02        1.2480    6   1   1         8
                76.98          2.21        1.2386    3   3   3         4
                79.70          2.01        1.2031    6   2   1         8
                80.82          2.39        1.1892    5   4   1         8
                81.22          1.29        1.1844    5   3   2         8
                83.45          2.11        1.1583    6   0   2         8
                84.85          1.53        1.1428    4   3   3         8
                85.01          1.05        1.1410    2   2   4         4
                85.96          2.51        1.1308    5   1   3         8
                86.13          1.31        1.1291    3   0   4         8
                87.24          1.26        1.1175    3   1   4         8
                87.90          1.11        1.1108    6   2   2         8
                89.29          1.22        1.0971    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.