Birnessite
      Post J E, Veblen D R
      American Mineralogist 75 (1990) 477-489
      Crystal structure determinations of synthetic sodium, magnesium and potassium
      birnessite using TEM and the Rietveld method
      Sample: K-birn
      _database_code_amcsd 0001302

      CELL PARAMETERS:    5.1490   2.8430   7.1760   90.000  100.760   90.000
      SPACE GROUP: C2/m      
      X-RAY WAVELENGTH:     1.541838
      Cell Volume:    103.200
      Density (g/cm3):      3.541
      MAX. ABS. INTENSITY / VOLUME**2:      64.60492174    
      RIR:      5.940
      RIR based on corundum from Acta Crystallographica A38 (1982) 733-739
               2-THETA      INTENSITY    D-SPACING   H   K   L   Multiplicity
                12.56        100.00        7.0498    0   0   1         2
                25.27         35.91        3.5249    0   0   2         2
                35.40          4.85        2.5359   -2   0   1         2
                35.49          3.05        2.5292    2   0   0         2
                36.25          5.41        2.4784    1   1   0         4
                37.34         16.82        2.4080   -1   1   1         4
                39.63          1.68        2.2739    1   1   1         4
                40.06         14.96        2.2508    2   0   1         2
                42.63         16.15        2.1207   -1   1   2         4
                46.69          3.65        1.9454    1   1   2         4
                47.65          2.89        1.9084   -2   0   3         2
                48.03          4.47        1.8943    2   0   2         2
                51.05         12.86        1.7889   -1   1   3         4
                51.88          1.69        1.7625    0   0   4         2
                56.36          3.01        1.6323    1   1   3         4
                57.92          1.66        1.5921   -2   0   4         2
                58.38          3.84        1.5807    2   0   3         2
                61.73          2.67        1.5027   -1   1   4         4
                63.37          3.28        1.4678   -3   1   1         4
                64.22          5.43        1.4503    3   1   0         4
                65.55          4.37        1.4241   -3   1   2         4
                65.68          3.31        1.4215    0   2   0         2
                67.18          1.60        1.3935    0   2   1         4
                68.03          4.18        1.3780    1   1   4         4
                68.06          1.39        1.3775    3   1   1         4
                70.08          1.86        1.3428   -2   0   5         2
                71.57          2.42        1.3183    0   2   2         4
                74.29          1.33        1.2767   -1   1   5         4
                74.89          1.20        1.2679   -4   0   2         2
                79.80          2.37        1.2019    2   2   1         4
                81.58          1.39        1.1800    1   1   5         4
                85.38          1.12        1.1370    2   2   2         4
================================================================================
       XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs
  For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.