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 = 37.6 GPa using ruby-scale
      Note: P = 39.1 GPa using MgO-scale
      _database_code_amcsd 0004690

      CELL PARAMETERS:    3.9770   3.9770   3.9770   90.000   90.000   90.000
      SPACE GROUP: Fm3m      
      X-RAY WAVELENGTH:     1.541838
      Cell Volume:     62.902
      Density (g/cm3):      4.255
      MAX. ABS. INTENSITY / VOLUME**2:      38.57472478    
      RIR:      2.952
      RIR based on corundum from Acta Crystallographica A38 (1982) 733-739
               2-THETA      INTENSITY    D-SPACING   H   K   L   Multiplicity
                39.24         12.14        2.2961    1   1   1         8
                45.62        100.00        1.9885    2   0   0         6
                66.50         48.25        1.4061    2   2   0        12
                80.02          6.40        1.1991    3   1   1        24
                84.37         13.16        1.1481    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.