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 = 6.5 GPa using ruby-scale
      Note: P = 6.6 GPa using MgO-scale
      _database_code_amcsd 0004701

      CELL PARAMETERS:    4.1580   4.1580   4.1580   90.000   90.000   90.000
      SPACE GROUP: Fm3m      
      X-RAY WAVELENGTH:     1.541838
      Cell Volume:     71.888
      Density (g/cm3):      3.723
      MAX. ABS. INTENSITY / VOLUME**2:      34.74489205    
      RIR:      3.038
      RIR based on corundum from Acta Crystallographica A38 (1982) 733-739
               2-THETA      INTENSITY    D-SPACING   H   K   L   Multiplicity
                37.46         11.25        2.4006    1   1   1         8
                43.53        100.00        2.0790    2   0   0         6
                63.26         49.94        1.4701    2   2   0        12
                75.89          6.35        1.2537    3   1   1        24
                79.92         13.51        1.2003    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.