Phase-X
      Mancini F, Harlow G E, Cahill C L
      American Mineralogist 87 (2002) 302-306
      The crystal structure and cation ordering of phase-X -
      (K1-x-n)2(Mg1-n[Al,Cr]n)2Si2O7H2x: A potential K- and H-bearing
      phase in the mantle
      _database_code_amcsd 0002757

      CELL PARAMETERS:    5.0280   5.0280  13.2160   90.000   90.000  120.000
      SPACE GROUP: P6_3cm    
      X-RAY WAVELENGTH:     1.541838
      Cell Volume:    289.348
      Density (g/cm3):      5.166
      MAX. ABS. INTENSITY / VOLUME**2:      67.59937269    
      RIR:      4.261
      RIR based on corundum from Acta Crystallographica A38 (1982) 733-739
               2-THETA      INTENSITY    D-SPACING   H   K   L   Multiplicity
                13.40        100.00        6.6080    0   0   2         1
                20.40         13.96        4.3544    1   0   0         6
                24.48         33.02        3.6359    1   0   2         6
                26.99         21.55        3.3040    0   0   4         1
                34.06         69.01        2.6321    1   0   4         6
                35.71         75.77        2.5140    1   1   0         6
                36.38          3.24        2.4697    1   1   1         6
                38.31         58.29        2.3497    1   1   2         6
                40.97         15.64        2.2027    0   0   6         1
                41.35          7.05        2.1835    1   1   3         6
                41.48          2.72        2.1772    2   0   0         6
                43.78          3.14        2.0678    2   0   2         6
                45.33         50.15        2.0007    1   1   4         6
                46.19          2.69        1.9655    1   0   6         6
                50.18         15.20        1.8180    2   0   4         6
                55.46          6.61        1.6567    1   1   6         6
                55.64          6.84        1.6520    0   0   8         1
                55.86          1.12        1.6458    2   1   0        12
                57.73          2.11        1.5970    2   1   2        12
                59.72          1.39        1.5484    2   0   6         6
                59.88          1.00        1.5446    1   0   8         6
                63.11         13.61        1.4732    2   1   4        12
                64.16         17.08        1.4515    3   0   0         6
                65.88          2.33        1.4177    3   0   2         6
                67.89         20.83        1.3806    1   1   8         6
                70.92          2.70        1.3289    3   0   4         6
                75.66          1.40        1.2570    2   2   0         6
                79.00          4.64        1.2120    3   0   6         6
                82.02          1.08        1.1748    2   2   4         6
                82.45          2.90        1.1698    1   1  10         6
                85.63          1.55        1.1343    3   1   4        12
                89.99          6.05        1.0904    3   0   8         6
================================================================================
       XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs
  For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.