Periclase
      Jacobsen S D, Holl C M, Adams K A, Fischer R A, Martin E S, Bina C R, Lin J F,
      Prakapenka V B, Kubo A, Dera P
      American Mineralogist 93 (2008) 1823-1828
      Compression of single-crystal magnesium oxide to 118 GPa and a ruby pressure
      gauge for helium pressure media
      Note: P = 73.9 GPa
      _database_code_amcsd 0004754

      CELL PARAMETERS:    3.8560   3.8560   3.8560   90.000   90.000   90.000
      SPACE GROUP: Fm3m      
      X-RAY WAVELENGTH:     1.541838
      Cell Volume:     57.334
      Density (g/cm3):      4.669
      MAX. ABS. INTENSITY / VOLUME**2:      41.37069589    
      RIR:      2.885
      RIR based on corundum from Acta Crystallographica A38 (1982) 733-739
               2-THETA      INTENSITY    D-SPACING   H   K   L   Multiplicity
                40.52         12.84        2.2263    1   1   1         8
                47.14        100.00        1.9280    2   0   0         6
                68.87         47.16        1.3633    2   2   0        12
                83.07          6.46        1.1626    3   1   1        24
                87.67         13.04        1.1131    2   2   2         8
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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.