Portlandite
      Henderson D M, Gutowsky H S
      American Mineralogist 47 (1962) 1231-1251
      A nuclear magnetic resonance determination of the hydrogen positions in Ca(OH)2
      T = -190 C
      _database_code_amcsd 0000116

      CELL PARAMETERS:    3.5850   3.5850   4.8710   90.000   90.000  120.000
      SPACE GROUP: P-3m1     
      X-RAY WAVELENGTH:     1.541838
      Cell Volume:     54.216
      Density (g/cm3):      2.269
      MAX. ABS. INTENSITY / VOLUME**2:      23.80613776    
      RIR:      3.416
      RIR based on corundum from Acta Crystallographica A38 (1982) 733-739
               2-THETA      INTENSITY    D-SPACING   H   K   L   Multiplicity
                18.21         63.98        4.8710    0   0   1         2
                28.75         16.97        3.1047    1   0   0         6
                34.25          2.54        2.6181    1   0   1         6
                34.25         97.46        2.6181    0   1   1         6
                47.44         17.52        1.9162    1   0   2         6
                47.44         23.93        1.9162    0   1   2         6
                50.95         27.79        1.7925    1   1   0         6
                54.55         14.51        1.6822    1   1   1        12
                56.69          1.12        1.6237    0   0   3         2
                59.55          1.91        1.5524    2   0   0         6
                62.83          9.84        1.4791    2   0   1         6
                64.80          1.16        1.4388    0   1   3         6
                64.80          9.40        1.4388    1   0   3         6
                72.16          4.56        1.3091    2   0   2         6
                72.16          3.33        1.3091    0   2   2         6
                78.55          1.40        1.2177    0   0   4         2
                79.68          1.96        1.2034    1   1   3        12
                85.03          1.99        1.1408    1   2   1        12
                85.69          1.15        1.1337    1   0   4         6
                86.80          3.08        1.1220    0   2   3         6
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       XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs
  For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.