Clausthalite
Diffraction data computed using the structure from the paper listed below, 
along with the cell parameters refined from single crystal data of R070169
      Noda Y, Masumoto K, Ohba S, Saito Y, Toriumi K, Iwata Y, Shibuya I
      Acta Crystallographica C43 (1987) 1443-1445
      Temperature dependence of atomic thermal parameters of lead chalcogenides, PbS,
      PbSe and PbTe
      Locality: synthetic
      Sample: T = 298 K
      _database_code_amcsd 0010048

      CELL PARAMETERS:   6.1190  6.1190  6.1190   90.000   90.000   90.000
      SPACE GROUP: Fm3m      

           ATOM        X         Y         Z     OCCUPANCY  ISO(B)
            Pb     0.00000   0.00000   0.00000     1.000     1.340
            Se     0.50000   0.50000   0.50000     1.000     1.070

            X-RAY WAVELENGTH:     1.541838
            BOUNDS ON TWO THETA:    5.0  90.0
            LIMITS IMPOSED ON THE INDICES ARE:  +/-  5 +/-  5 +/-  5
            MAX. ABS. INTENSITY / VOLUME**2:      500.8117609    
            The INTENSITY cut off value is   1.00

               2-THETA      INTENSITY    D-SPACING   H   K   L
                25.21         35.95        3.5328    1   1   1
                29.19        100.00        3.0595    2   0   0
                41.75         71.91        2.1634    2   2   0
                49.40         16.51        1.8449    3   1   1
                51.75         24.20        1.7664    2   2   2
                60.52         10.68        1.5297    4   0   0
                66.62          5.99        1.4038    3   3   1
                68.59         27.69        1.3683    4   2   0
                76.23         19.37        1.2490    4   2   2
                81.79          3.03        1.1776    5   1   1
                81.79          1.01        1.1776    3   3   3
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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.