Carbon
      Ownby P D, Yang X, Liu J
      Journal of the American Ceramic Society 75 (1992) 1876-1883
      Calculated X-ray diffraction data for diamond polytypes
      Note: hexagonal, 2H structure known as lonsdaleite
      Note: theoretically calculated structure values
      _database_code_amcsd 0014066

      CELL PARAMETERS:    2.5221   2.5221   4.1186   90.000   90.000  120.000
      SPACE GROUP: P6_3/mmc  
      X-RAY WAVELENGTH:     1.541838
      Cell Volume:     22.688
      Density (g/cm3):      3.516
      MAX. ABS. INTENSITY / VOLUME**2:      6.159104241    
      RIR:      0.570
      RIR based on corundum from Acta Crystallographica A38 (1982) 733-739
               2-THETA      INTENSITY    D-SPACING   H   K   L   Multiplicity
                41.34        100.00        2.1842    1   0   0         6
                43.97         52.16        2.0593    0   0   2         2
                47.10         52.11        1.9296    1   0   1        12
                61.93         19.52        1.4984    1   0   2        12
                75.37         38.10        1.2610    1   1   0         6
                83.10         36.53        1.1623    1   0   3        12
                89.81          5.96        1.0921    2   0   0         6
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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.