GaN
      Xu Y N, Ching W Y
      Physical Review B48 (1993) 4335-4351
      Electronic, optical, and structural properties of some wurtzite crystals
      _database_code_amcsd 0015172

      CELL PARAMETERS:    3.1900   3.1900   5.1890   90.000   90.000  120.000
      SPACE GROUP: P6_3mc    
      X-RAY WAVELENGTH:     1.541838
      Cell Volume:     45.729
      Density (g/cm3):      6.080
      MAX. ABS. INTENSITY / VOLUME**2:      134.3147577    
      RIR:      7.193
      RIR based on corundum from Acta Crystallographica A38 (1982) 733-739
               2-THETA      INTENSITY    D-SPACING   H   K   L   Multiplicity
                32.41         43.78        2.7626    1   0   0         6
                34.57         35.58        2.5945    0   0   2         1
                36.86        100.00        2.4386    1   0   1         6
                48.11         19.79        1.8912    1   0   2         6
                57.81         27.90        1.5950    1   1   0         6
                63.45         28.23        1.4660    1   0   3         6
                67.85          3.97        1.3813    2   0   0         6
                69.13         23.39        1.3588    1   1   2         6
                70.56         13.23        1.3348    2   0   1         6
                72.92          2.38        1.2973    0   0   4         1
                78.44          3.85        1.2193    2   0   2         6
                82.07          2.47        1.1742    1   0   4         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.