Helium
      Schuch A F, Mills R L
      Physical Review Letters 8 (1962) 469-470
      Structure of the gamma form of solid He4
      Locality: synthetic
      Sample: at T = 1.73 K & P = .003 GPa
      _database_code_amcsd 0015274

      CELL PARAMETERS:    3.6500   3.6500   5.9450   90.000   90.000  120.000
      SPACE GROUP: P6_3/mmc  
      X-RAY WAVELENGTH:     1.541838
      Cell Volume:     68.591
      Density (g/cm3):      0.194
      MAX. ABS. INTENSITY / VOLUME**2:     0.4021635925    
      RIR:      0.676
      RIR based on corundum from Acta Crystallographica A38 (1982) 733-739
               2-THETA      INTENSITY    D-SPACING   H   K   L   Multiplicity
                28.23         24.71        3.1610    1   0   0         6
                30.06         27.23        2.9725    0   0   2         2
                32.07        100.00        2.7910    1   0   1        12
                41.71         13.30        2.1654    1   0   2        12
                49.98         12.81        1.8250    1   1   0         6
                54.66         12.96        1.6790    1   0   3        12
                58.39          1.60        1.5805    2   0   0         6
                59.43         11.76        1.5553    1   1   2        12
                60.62          8.03        1.5274    2   0   1        12
                62.49          1.55        1.4863    0   0   4         2
                67.07          1.65        1.3955    2   0   2        12
                69.94          1.34        1.3450    1   0   4        12
                77.20          2.49        1.2356    2   0   3        12
                82.32          1.23        1.1713    2   1   1        24
                83.97          2.24        1.1524    1   1   4        12
                87.69          1.39        1.1129    1   0   5        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.