Sylvite
      Walker D, Verma P K, Cranswick L M D, Jones R L, Clark S M, Buhre S
      American Mineralogist 89 (2004) 204-210
      Halite-sylvite thermoelasticity
      Sample: r57761, T = 100 C, P = 3.9 kbar, cell volume = 245.43 ang**3
      _database_code_amcsd 0003205

      CELL PARAMETERS:    6.2610   6.2610   6.2610   90.000   90.000   90.000
      SPACE GROUP: Fm3m      
      X-RAY WAVELENGTH:     1.541838
      Cell Volume:    245.432
      Density (g/cm3):      2.017
      MAX. ABS. INTENSITY / VOLUME**2:      35.88237769    
      RIR:      5.792
      RIR based on corundum from Acta Crystallographica A38 (1982) 733-739
               2-THETA      INTENSITY    D-SPACING   H   K   L   Multiplicity
                28.51        100.00        3.1305    2   0   0         6
                40.76         63.33        2.2136    2   2   0        12
                50.50         19.42        1.8074    2   2   2         8
                59.01          8.04        1.5653    4   0   0         6
                66.82         20.02        1.4000    4   2   0        24
                74.20         13.64        1.2780    4   2   2        24
                88.30          3.95        1.1068    4   4   0        12
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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.