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 = 359.7 K
      Melilite group
      _database_code_amcsd 0008520

      CELL PARAMETERS:    7.8398   7.8398   5.0058   90.000   90.000   90.000
      SPACE GROUP: P-42_1m   
      X-RAY WAVELENGTH:     1.541838
      Cell Volume:    307.669
      Density (g/cm3):      2.942
      MAX. ABS. INTENSITY / VOLUME**2:      22.57994247    
      RIR:      2.499
      RIR based on corundum from Acta Crystallographica A38 (1982) 733-739
               2-THETA      INTENSITY    D-SPACING   H   K   L   Multiplicity
                15.99          9.57        5.5436    1   1   0         4
                17.72          1.69        5.0058    0   0   1         2
                21.06          7.26        4.2191    1   0   1         8
                22.68          3.14        3.9199    2   0   0         4
                23.95         11.36        3.7153    1   1   1         4
                25.40          4.13        3.5061    2   1   0         8
                28.93         23.10        3.0862    2   0   1         8
                31.14        100.00        2.8717    2   1   1         8
                32.30          3.91        2.7718    2   2   0         4
                35.88          1.64        2.5029    0   0   2         2
                36.23         16.27        2.4792    3   1   0         8
                37.07          5.51        2.4249    2   2   1         4
                37.73          6.47        2.3843    1   0   2         8
                38.88          6.73        2.3166    3   0   1         8
                39.50          2.73        2.2812    1   1   2         4
                40.61          1.59        2.2216    3   1   1         8
                44.47         13.24        2.0371    2   1   2         8
                45.48          2.39        1.9943    3   2   1         8
                46.32          5.91        1.9599    4   0   0         4
                47.84          6.72        1.9014    4   1   0         8
                49.04          4.12        1.8576    2   2   2         4
                49.32          9.99        1.8479    3   3   0         4
                51.41          9.35        1.7775    4   1   1         8
                51.91         19.90        1.7614    3   1   2         8
                52.18          6.27        1.7530    4   2   0         8
                52.81          3.40        1.7335    3   3   1         4
                55.03          1.16        1.6686    0   0   3         2
                56.02          2.44        1.6415    3   2   2         8
                57.70          1.79        1.5978    1   1   3         4
                60.28          1.53        1.5353    2   0   3         8
                61.55          4.48        1.5067    2   1   3         8
                62.47          1.37        1.4866    3   3   2         4
                63.27          2.80        1.4697    5   1   1         8
                65.27          4.85        1.4296    2   2   3         4
                66.48          2.71        1.4064    3   0   3         8
                66.94          9.38        1.3979    5   2   1         8
                67.60          3.05        1.3859    4   4   0         4
                70.51          1.77        1.3357    4   4   1         4
                70.93          1.44        1.3288    4   3   2         8
                72.31          3.33        1.3066    6   0   0         4
                73.47          1.15        1.2889    6   1   0         8
                75.56          1.37        1.2584    5   2   2         8
                75.86          4.59        1.2542    4   1   3         8
                76.05          1.22        1.2514    0   0   4         2
                76.29          1.09        1.2481    6   1   1         8
                77.00          2.31        1.2384    3   3   3         4
                79.69          2.06        1.2032    6   2   1         8
                80.81          2.47        1.1893    5   4   1         8
                81.21          1.31        1.1844    5   3   2         8
                83.45          2.13        1.1583    6   0   2         8
                84.86          1.58        1.1426    4   3   3         8
                85.05          1.08        1.1406    2   2   4         4
                85.97          2.56        1.1307    5   1   3         8
                86.16          1.34        1.1287    3   0   4         8
                87.27          1.25        1.1172    3   1   4         8
                87.90          1.16        1.1108    6   2   2         8
                89.30          1.23        1.0970    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.