Hydrogen
      Mao H K, Jephcoat A P, Hemley R J, Finger L W, Zha C S, Hazen R M, Cox D E
      Science 239 (1988) 1131-1133
      Synchrotron X-ray diffraction measurements of single-crystal hydrogen to
      26.5 Gigapascals
      Locality: synthetic
      Sample: at P = 15.0 GPa, T = 300 K
      _database_code_amcsd 0015434

      CELL PARAMETERS:    2.3930   2.3930   3.8850   90.000   90.000  120.000
      SPACE GROUP: P6_3/mmc  
      X-RAY WAVELENGTH:     1.541838
      Cell Volume:     19.267
      Density (g/cm3):      0.174
      MAX. ABS. INTENSITY / VOLUME**2:     0.6593538905E-01
      RIR:      0.124
      RIR based on corundum from Acta Crystallographica A38 (1982) 733-739
               2-THETA      INTENSITY    D-SPACING   H   K   L   Multiplicity
                43.68         35.48        2.0724    1   0   0         6
                46.77         32.33        1.9425    0   0   2         2
                49.87        100.00        1.8285    1   0   1        12
                65.91          5.63        1.4173    1   0   2        12
                80.23          1.01        1.1965    1   1   0         6
                89.17          2.36        1.0982    1   0   3        12
================================================================================
       XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs
  For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.