Quartz
Diffraction data computed using the structure from the paper listed below,
along with the cell parameters refined from the powder pattern for R060604
      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

      CELL PARAMETERS:   4.914493   4.914493   5.406190   90.00000   90.00000   120.0000
      ALTERNATE SETTING FOR SPACE GROUP: P3_221
      X-RAY WAVELENGTH:     1.541838
               2-THETA      INTENSITY    D-SPACING   H   K   L
                20.92         19.93        4.2561    1   0   0
                26.70         69.90        3.3441    0   1   1
                26.70         30.10        3.3441    1   0   1
                36.60          7.13        2.4572    1   1   0
                39.52          1.01        2.2818    0   1   2
                39.52          6.18        2.2818    1   0   2
                40.34          3.19        2.2370    1   1   1
                42.50          5.25        2.1280    2   0   0
                45.85          1.00        1.9802    0   2   1
                45.85          2.09        1.9802    2   0   1
                50.19         12.58        1.8183    1   1   2
                54.92          3.09        1.6721    0   2   2
                55.38          1.61        1.6594    0   1   3
                60.01          4.11        1.5418    2   1   1
                60.01          4.94        1.5418    1   2   1
                64.08          1.72        1.4532    1   1   3
                67.79          1.38        1.3824    2   1   2
                67.79          4.18        1.3824    1   2   2
                68.19          1.36        1.3752    0   2   3
                68.19          5.31        1.3752    2   0   3
                68.36          4.13        1.3722    0   3   1
                73.51          1.73        1.2882    1   0   4
                75.70          1.91        1.2562    3   0   2
                79.92          2.30        1.2001    2   1   3
                81.21          2.41        1.1842    1   1   4
                81.21          2.41        1.1842    1   1   4
       XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs
  For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.