Silicon
      Olijnyk H, Sikka S K, Holzapfel W B
      Physics Letters 103A (1984) 137-140
      Structural phase transitions in Si and Ge under pressures up to 50 GPa
      Locality: synthetic
      Sample: at P = 43 GPa
      Note: phase VII, structure stable above 43 GPa
      _database_code_amcsd 0015304

      CELL PARAMETERS:    2.4440   2.4440   4.1520   90.000   90.000  120.000
      SPACE GROUP: P6_3/mmc  
      X-RAY WAVELENGTH:     1.541838
      Cell Volume:     21.478
      Density (g/cm3):      4.342
      MAX. ABS. INTENSITY / VOLUME**2:      51.55421516    
      RIR:      3.866
      RIR based on corundum from Acta Crystallographica A38 (1982) 733-739
               2-THETA      INTENSITY    D-SPACING   H   K   L   Multiplicity
                42.72         24.42        2.1166    1   0   0         6
                43.60         30.57        2.0760    0   0   2         2
                48.26        100.00        1.8857    1   0   1        12
                62.69         14.45        1.4821    1   0   2        12
                78.23          4.86        1.2220    1   1   0         6
                83.45         18.30        1.1583    1   0   3        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.