Erbium
      Spedding F H, Daane A H, Herrmann K W
      Acta Crystallographica 9 (1956) 559-563
      The crystal structures and lattice parameters of high-purity scandium,
      yttrium and the rare earth metals
      Locality: synthetic
      Note: sample 99.8% pure
      _database_code_amcsd 0009177

      CELL PARAMETERS:    3.5588   3.5588   5.5874   90.000   90.000  120.000
      SPACE GROUP: P6_3/mmc  
      X-RAY WAVELENGTH:     1.541838
      Cell Volume:     61.284
      Density (g/cm3):      9.063
      MAX. ABS. INTENSITY / VOLUME**2:      636.8017251    
      RIR:     22.879
      RIR based on corundum from Acta Crystallographica A38 (1982) 733-739
               2-THETA      INTENSITY    D-SPACING   H   K   L   Multiplicity
                28.97         24.10        3.0820    1   0   0         6
                32.04         24.52        2.7937    0   0   2         2
                33.20        100.00        2.6987    1   0   1        12
                43.73         14.72        2.0699    1   0   2        12
                51.35         17.36        1.7794    1   1   0         6
                57.85         17.17        1.5940    1   0   3        12
                60.04          2.50        1.5410    2   0   0         6
                61.82         18.03        1.5008    1   1   2        12
                62.52         12.97        1.4855    2   0   1        12
                66.99          2.24        1.3968    0   0   4         2
                69.69          2.92        1.3493    2   0   2        12
                74.59          2.29        1.2723    1   0   4        12
                80.98          5.19        1.1873    2   0   3        12
                85.07          2.96        1.1404    2   1   1        24
                89.12          5.18        1.0987    1   1   4        12
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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.