Quartz
Diffraction data computed using the structure from the paper listed below,
along with the cell parameters refined from the powder pattern for R110108
      Levien L, Prewitt C T, Weidner D J
      American Mineralogist 65 (1980) 920-930
      Structure and elastic properties of quartz at pressure
      P = 1 atm
      _database_code_amcsd 0000789

      CELL PARAMETERS:   4.9211  4.9211  5.4094   90.000   90.000  120.000
      ALTERNATE SETTING FOR SPACE GROUP: P3_221    

           ATOM        X         Y         Z     OCCUPANCY  ISO(B)
            Si     0.46970   0.00000   0.00000     1.000     0.617
            O      0.41350   0.26690   0.11910     1.000     1.060

            X-RAY WAVELENGTH:     1.541838
            BOUNDS ON TWO THETA:    5.0  90.0
            LIMITS IMPOSED ON THE INDICES ARE:  +/-  3 +/-  3 +/-  4
            MAX. ABS. INTENSITY / VOLUME**2:      35.06551285    
            The INTENSITY cut off value is   1.00

               2-THETA      INTENSITY    D-SPACING   H   K   L
                20.84         19.93        4.2618    1   0   0
                26.63         69.90        3.3477    0   1   1
                26.63         30.10        3.3477    1   0   1
                36.52          7.14        2.4606    1   1   0
                39.46          1.01        2.2836    0   1   2
                39.46          6.18        2.2836    1   0   2
                40.27          3.19        2.2397    1   1   1
                42.42          5.25        2.1309    2   0   0
                45.76          1.00        1.9826    0   2   1
                45.76          2.10        1.9826    2   0   1
                50.12         12.59        1.8201    1   1   2
                54.85          3.09        1.6738    0   2   2
                55.32          1.61        1.6606    0   1   3
                59.92          4.94        1.5438    1   2   1
                59.92          4.11        1.5438    2   1   1
                64.02          1.72        1.4544    1   1   3
                67.70          4.19        1.3840    1   2   2
                67.70          1.38        1.3840    2   1   2
                68.12          1.36        1.3765    0   2   3
                68.12          5.32        1.3765    2   0   3
                68.26          4.13        1.3740    0   3   1
                73.46          1.73        1.2890    1   0   4
                75.61          1.91        1.2577    3   0   2
                79.84          2.30        1.2013    2   1   3
                81.16          2.41        1.1851    1   1   4
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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.