Chlormayenite
Diffraction data computed using the structure from the paper listed below,  along with the cell parameters refined from single crystal data of R140780
      Galuskin E V, Kusz J, Armbruster T, Bailau R, Galuskina I O, Ternes B, Murashko M
      Mineralogical Magazine 76 (2012) 707-716
      A reinvestigation of mayenite from the type locality, the Ettringer Bellerberg
      volcano near Mayen, Eifel district, Germany
      Locality: Ettringer Bellerberg volcano near Mayen, Eifel district, Germany
      _database_code_amcsd 0018992

      CELL PARAMETERS:  12.0508 12.0508 12.0508   90.000   90.000   90.000
      SPACE GROUP: I-43d     

           ATOM        X         Y         Z     OCCUPANCY  ISO(B)
            Ca     0.13784   0.00000   0.25000     1.000     0.468
            Al     0.01617   0.01617   0.01617     0.943     0.366
            Fe     0.01617   0.01617   0.01617     0.057     0.366
            Al     0.87500   0.00000   0.25000     1.000     0.257
            O      0.03539   0.44472   0.15013     1.000     0.538
            O      0.18393   0.18393   0.18393     0.905     0.614
            O      0.20100   0.28490   0.10550     0.094     0.584
            Cl     0.37500   0.00000   0.25000     0.208     0.726

            X-RAY WAVELENGTH:     1.541838
            BOUNDS ON TWO THETA:    5.0  90.0
            LIMITS IMPOSED ON THE INDICES ARE:  +/- 11 +/- 11 +/- 11
            MAX. ABS. INTENSITY / VOLUME**2:      15.59058164    
            The INTENSITY cut off value is   1.00

               2-THETA      INTENSITY    D-SPACING   H   K   L
                18.03         87.30        4.9197    2   1   1
                20.85          4.54        4.2606    2   2   0
                23.34          5.79        3.8108    3   1   0
                27.70         11.32        3.2207    3   2   1
                29.65         35.79        3.0127    4   0   0
                33.25        100.00        2.6946    4   2   0
                34.92          6.98        2.5692    3   3   2
                36.53         47.40        2.4599    4   2   2
                38.08          4.11        2.3634    5   1   0
                41.02         31.09        2.2002    5   2   1
                42.43          1.17        2.1303    4   4   0
                43.80          1.71        2.0667    5   3   0
                46.45          6.19        1.9549    6   1   1
                46.45         20.87        1.9549    5   3   2
                48.99          3.65        1.8595    5   4   1
                51.43          3.19        1.7768    6   3   1
                52.62         11.78        1.7394    4   4   4
                53.79          3.73        1.7042    7   1   0
                54.94         30.86        1.6711    6   4   0
                56.08          3.49        1.6399    6   3   3
                56.08          2.99        1.6399    5   5   2
                57.20         38.88        1.6104    6   4   2
                60.49          2.42        1.5305    7   3   2
                60.49          1.77        1.5305    6   5   1
                61.56          7.38        1.5064    8   0   0
                62.63          5.76        1.4834    7   4   1
                66.78          5.67        1.4009    7   4   3
                66.78          5.94        1.4009    7   5   0
                68.80          1.67        1.3645    7   5   2
                69.81          7.53        1.3473    8   4   0
                70.80          1.34        1.3308    9   1   0
                71.79         13.69        1.3149    8   4   2
                72.78          1.47        1.2995    9   2   1
                73.76          5.60        1.2846    6   6   4
                74.73          2.82        1.2703    7   5   4
                74.73          1.98        1.2703    8   5   1
                76.67          1.38        1.2429    9   3   2
                78.59          1.87        1.2173    8   5   3
                78.59          2.91        1.2173    9   4   1
                81.44          2.11        1.1817   10   2   0
                84.28          2.01        1.1490    7   6   5
                87.10          7.53        1.1189    8   6   4
                87.10          5.41        1.1189   10   4   0
                88.04          1.14        1.1094   10   3   3
                88.98          6.58        1.1001   10   4   2
                89.92          2.25        1.0910    8   7   3
                89.92          1.13        1.0910    9   5   4
================================================================================
       XPOW Copyright 1993 Bob Downs, Ranjini Swaminathan and Kurt Bartelmehs
  For reference, see Downs et al. (1993) American Mineralogist 78, 1104-1107.