Institute of Experimental Mineralogy
                 Russian Academy of Sciences
     -------------------------------------------------
           142432, Chernogolovka, Moscow district
             A.V. Chichagov  +7(496)52-22320

                            ***

          ***      W W W - X R A Y P O L       ***
                  ***********************
ARMALCOLITE

11, at 4.34 GPa

MgTi(2)O(5)


Orthorhombic  B bmm  Z = 4

Bbmm

15 .10 .1901

Ref.Str.:

         Yang H, Hazen R.M. (1999)

         * Amer. Mineral., 84, 130-137

Reserv:

         In original - karrooite[7].

         All structure data from 0.0 GPa upto 7.5 GPa

         see in the original.   N.A.D.

                   Initial data from BDM-file 

   Lattice parameters (cub. angs.,degr.):

             a =   9.6737   alpha =   90.0 
             b =   9.8769   beta  =   90.0 
             c =   3.7271   gamma =   90.0 

    Unit cell volume (cub. angs.) =   356.11

    Molar volume ( cub.cm/mol.) =    53.62

  Co-ordinates, thermal parameters, occupation for atomic positions:

NoP   x/a     y/b     z/c    B(j)   atom  / occupation

   1 0.8074  0.25    0.0      0.49   Mg    = 0.51, Ti    = 0.49
   2 0.1357  0.4367  0.0      0.48   Ti    = 0.76, Mg    = 0.24
   3 0.2339  0.25    0.0      0.89   O     = 1.00
   4 0.0474  0.8828  0.0      0.68   O     = 1.00
   5 0.3123  0.9307  0.0      0.7    O     = 1.00


  Co-ordinates for all atomic positions :

   No       NoP      x/a        y/b       z/c 

     1       1     0.8074     0.25       0.0   
     2       2     0.1357     0.4367     0.0   
     3       3     0.2339     0.25       0.0   
     4       4     0.0474     0.8828     0.0   
     5       5     0.3123     0.9307     0.0   
     6       1     0.1926     0.75       0.0   
     7       2     0.8643     0.5633     0.0   
     8       3     0.7661     0.75       0.0   
     9       4     0.9526     0.1172     0.0   
    10       5     0.6877     0.0693     0.0   
    11       2     0.1357     0.0633     0.0   
    12       4     0.0474     0.6172     0.0   
    13       5     0.3123     0.5693     0.0   
    14       2     0.8643     0.9367     0.0   
    15       4     0.9526     0.3828     0.0   
    16       5     0.6877     0.4307     0.0   
    17       1     0.6926     0.75       0.5   
    18       2     0.3643     0.9367     0.5   
    19       3     0.2661     0.75       0.5   
    20       4     0.4526     0.3828     0.5   
    21       5     0.1877     0.4307     0.5   
    22       1     0.3074     0.25       0.5   
    23       2     0.6357     0.0633     0.5   
    24       3     0.7339     0.25       0.5   
    25       4     0.5474     0.6172     0.5   
    26       5     0.8123     0.5693     0.5   
    27       2     0.3643     0.5633     0.5   
    28       4     0.4526     0.1172     0.5   
    29       5     0.1877     0.0693     0.5   
    30       2     0.6357     0.4367     0.5   
    31       4     0.5474     0.8828     0.5   
    32       5     0.8123     0.9307     0.5   


X-ray density (g/cm cub.)   =      3.73

MU (1/cm) =     406.192    Mass attenuation coefficient (cm**2/g) =    108.868

 Selected interatomic distances (cation-anion,anion-anion):

 NoP    Atom              Rad.sph.      C.N.    Distance     NoP N.
                           (angs.)               (angs.)

    1   Mg   ,Ti             2.568        6
                                                 1.9218       4
                                                 2.1275       5
                                                 1.9218       4
                                                 2.1275       5
                                                 1.9946       3
                                                 1.9946       3
    2   Ti   ,Mg             2.568        6
                                                 2.0743       3
                                                 1.9769       4
                                                 2.1526       5
                                                 1.8495       4
                                                 1.9312       5
                                                 1.9312       5
    3    O                   3.264       12
                                                 3.2436       5
                                                 3.0208       4
                                                 3.2436       5
                                                 3.0208       4
                                                 3.1095       4
                                                 3.1095       4
                                                 2.6188       5
                                                 2.6188       5
                                                 3.1095       4
                                                 3.1095       4
                                                 2.6188       5
                                                 2.6188       5
    4    O                   3.264       10
                                                 2.6059       5
                                                 3.0208       3
                                                 2.4902       4
                                                 2.6233       4
                                                 3.1095       3
                                                 3.1095       3
                                                 2.9509       5
                                                 2.9509       5
                                                 2.9781       5
                                                 2.9781       5
    5    O                   3.264       10
                                                 3.2436       3
                                                 2.6059       4
                                                 2.6188       3
                                                 2.6188       3
                                                 2.9509       4
                                                 2.9509       4
                                                 2.6076       5
                                                 2.6076       5
                                                 2.9781       4
                                                 2.9781       4

  X-ray diffraction powder data (II),  X-Ray W.L. =   1.54056(angs.):

  No   H   K   L   Theta 2*Theta    S       LPG   MF        F          I int.
                    ( degree )                                         *100

    1   0   2   0  8.973  17.947   0.101   79.28    2       51.5      331.8
    2   2   0   0  9.164  18.327   0.103   75.93    2       84.4      852.2
    3   2   1   0 10.214  20.428   0.115   60.69    4       14.7       41.2
    4   1   0   1 12.796  25.592   0.144   37.91    4      135.7     2201.8
    5   2   2   0 12.88   25.76    0.145   37.39    4       34.9      143.6
    6   1   1   1 13.58   27.161   0.152   33.43    8       18.5       71.9
    7   1   2   1 15.717  31.434   0.176   24.46    8       27.2      114.6
    8   2   3   0 16.441  32.881   0.184   22.2     4      147.7     1527.6
    9   0   4   0 18.177  36.354   0.202   17.83    2       17.8        8.9
   10   3   0   1 18.413  36.827   0.205   17.33    4       76.0      315.7
   11   4   0   0 18.573  37.145   0.207   17.01    2       66.2      117.4
   12   1   3   1 18.794  37.588   0.209   16.57    8       53.8      302.5
   13   3   1   1 18.987  37.974   0.211   16.2     8       10.8       11.9
   14   4   1   0 19.142  38.284   0.213   15.91    4       16.5       13.7
   15   2   4   0 20.503  41.005   0.227   13.66    4       82.0      289.5
   16   3   2   1 20.627  41.254   0.229   13.48    8       10.4        9.2
   17   4   2   0 20.772  41.544   0.23    13.27    4       94.7      375.2
   18   1   4   1 22.494  44.987   0.248   11.09    8       16.5       19.0
   19   3   3   1 23.147  46.293   0.255   10.4     8       39.4      101.6
   20   4   3   0 23.279  46.557   0.257   10.27    4      123.6      495.0
   21   0   0   2 24.415  48.83    0.268    9.21    2      228.5      758.8
   22   2   5   0 24.911  49.822   0.273    8.8     4       93.7      243.7
   23   0   2   2 26.218  52.436   0.287    7.83    4       33.5       27.7
   24   2   0   2 26.293  52.585   0.288    7.78    4       55.3       75.2
   25   3   4   1 26.356  52.712   0.288    7.74    8       64.5      203.1
   26   4   4   0 26.476  52.952   0.289    7.66    4        9.9        2.4
   27   1   5   1 26.644  53.288   0.291    7.55    8       22.8       24.7
   28   5   0   1 26.652  53.305   0.291    7.55    4       20.6       10.1
   29   2   1   2 26.729  53.458   0.292    7.5     8        9.8        4.5
   30   5   1   1 27.085  54.169   0.296    7.27    8       25.8       30.5
   31   0   6   0 27.9    55.8     0.304    6.8     2      156.8      263.7
   32   2   2   2 28.009  56.019   0.305    6.74    8       24.4       25.3
   33   5   2   1 28.354  56.708   0.308    6.56    8       90.7      340.6
   34   6   0   0 28.539  57.078   0.31     6.46    2       59.8       36.5
   35   6   1   0 28.952  57.905   0.314    6.25    4       66.3       86.7
   36   2   6   0 29.623  59.245   0.321    5.94    4       61.9       71.8
   37   2   3   2 30.063  60.126   0.325    5.75    8      109.1      431.9
   38   3   5   1 30.121  60.242   0.326    5.72    8       68.8      170.9
   39   6   2   0 30.17   60.341   0.326    5.7     4       26.4       12.5
   40   4   5   0 30.231  60.462   0.327    5.68    4        1.2        0.0
   41   5   3   1 30.393  60.786   0.328    5.61    8      105.6      394.3
   42   1   6   1 31.178  62.356   0.336    5.3     8       53.8       96.8
   43   0   4   2 31.188  62.376   0.336    5.3     4       17.2        4.9
   44   4   0   2 31.454  62.909   0.339    5.2     4       54.6       48.9
   45   4   1   2 31.844  63.689   0.342    5.06    8        5.5        1.0
   46   6   3   0 32.139  64.277   0.345    4.96    4       51.3       41.1
   47   2   4   2 32.805  65.61    0.352    4.74    8       56.9       96.9
   48   4   2   2 33.0    65.999   0.354    4.68    8       70.4      146.3
   49   5   4   1 33.119  66.239   0.355    4.65    8       43.3       55.0
   50   3   6   1 34.372  68.744   0.366    4.3     8       58.5       92.8
   51   4   6   0 34.475  68.949   0.367    4.27    4       37.7       19.1
   52   2   7   0 34.658  69.315   0.369    4.23    4       61.7       50.8
   53   6   4   0 34.791  69.582   0.37     4.2     4       11.1        1.6
   54   4   3   2 34.881  69.761   0.371    4.17    8       90.1      213.9
   55   1   7   1 36.095  72.191   0.382    3.9     8       44.4       48.5
   56   2   5   2 36.167  72.334   0.383    3.88    8       69.9      119.6
   57   5   5   1 36.468  72.935   0.386    3.82    8       26.5       16.9
   58   7   0   1 36.475  72.949   0.386    3.82    4       43.7       23.0
   59   7   1   1 36.838  73.677   0.389    3.75    8       66.4      104.3
   60   4   4   2 37.442  74.884   0.395    3.64    8        7.4        1.3
   61   7   2   1 37.922  75.844   0.399    3.56    8       79.3      141.1
   62   6   5   0 38.075  76.149   0.4      3.53    4       58.8       38.5
   63   0   8   0 38.602  77.204   0.405    3.45    2       31.2        5.3
   64   0   6   2 38.634  77.268   0.405    3.44    4      120.1      156.7
   65   1   0   3 38.69   77.379   0.406    3.44    4       72.6       57.1
   66   1   1   3 39.046  78.093   0.409    3.38    8       10.5        2.4
   67   3   7   1 39.103  78.206   0.409    3.37    8       24.7       13.0
   68   6   0   2 39.179  78.358   0.41     3.36    4       47.8       24.2
   69   4   7   0 39.201  78.401   0.41     3.36    4       18.0        3.4
   70   6   1   2 39.534  79.069   0.413    3.32    8       53.1       59.0
   71   8   0   0 39.569  79.138   0.413    3.31    2        2.3        0.0
   72   7   3   1 39.706  79.412   0.415    3.29    8       20.7        8.9
   73   8   1   0 39.924  79.847   0.417    3.26    4        5.0        0.3
   74   2   8   0 40.084  80.168   0.418    3.24    4        6.2        0.4
   75   1   2   3 40.111  80.222   0.418    3.24    8       17.7        6.4
   76   2   6   2 40.116  80.232   0.418    3.24    8       47.5       46.0
   77   5   6   1 40.407  80.814   0.421    3.21    8        3.6        0.3
   78   6   2   2 40.596  81.191   0.422    3.18    8       19.1        7.3
   79   4   5   2 40.649  81.298   0.423    3.18    8        2.4        0.1
   80   8   2   0 40.982  81.965   0.426    3.14    4       50.2       24.9
   81   1   8   1 41.456  82.913   0.43     3.09    8        9.2        1.7
   82   3   0   3 41.639  83.278   0.431    3.07    4       56.2       30.6
   83   1   3   3 41.871  83.741   0.433    3.05    8       44.4       37.9
   84   6   6   0 41.97   83.939   0.434    3.04    4       39.1       14.7
   85   3   1   3 41.99   83.979   0.434    3.04    8       12.5        3.0
   86   7   4   1 42.171  84.342   0.436    3.02    8       16.4        5.1
   87   6   3   2 42.352  84.703   0.437    3.01    8       41.0       31.9
   88   8   3   0 42.736  85.471   0.44     2.97    4       20.6        4.0
   89   3   2   3 43.039  86.078   0.443    2.95    8        1.7        0.1
   90   1   4   3 44.316  88.632   0.453    2.87    8        6.1        0.7
   91   3   8   1 44.372  88.743   0.454    2.86    8       21.7        8.5
   92   4   8   0 44.467  88.934   0.455    2.86    4       81.1       59.3
   93   4   6   2 44.499  88.998   0.455    2.85    8       32.2       18.7
   94   2   7   2 44.67   89.339   0.456    2.85    8       50.1       45.0
   95   3   3   3 44.783  89.566   0.457    2.84    8       23.8       10.2
   96   6   4   2 44.795  89.589   0.457    2.84    8        9.7        1.7
   97   5   7   1 44.957  89.914   0.459    2.83    8       17.6        5.5


  X-ray diffraction powder data (I)...X-Ray wave length =  1.54056 (angs.):

  No   H   K   L   Theta 2*Theta    d           I int   I int.n.  I p.h.n.   H(Si)
                    ( degree )   (angstrem)     *100                         *100

    1   0   2   0   8.973  17.947  4.93845      331.8     15.1     15.2     5.6
    2   2   0   0   9.164  18.327  4.83685      852.2     38.7     38.9     5.6
    3   2   1   0  10.214  20.428  4.34394       41.2      1.9      1.9     5.6
    4   1   0   1  12.796  25.592  3.4779      2201.8    100.0    100.0     5.6
    5   2   2   0  12.88   25.76   3.45553      143.6      6.5      6.5     5.6
    6   1   1   1  13.58   27.161  3.28046       71.9      3.3      3.3     5.6
    7   1   2   1  15.717  31.434  2.84352      114.6      5.2      5.2     5.6
    8   2   3   0  16.441  32.881  2.72164     1527.6     69.4     69.0     5.6
    9   3   0   1  18.413  36.827  2.43858      315.7     14.3     14.2     5.7
   10   4   0   0  18.573  37.145  2.41843      117.4      5.3      5.3     5.7
   11   1   3   1  18.794  37.588  2.39093      302.5     13.7     13.6     5.7
   12   2   4   0  20.503  41.005  2.19923      289.5     13.1     13.0     5.7
   13   4   2   0  20.772  41.544  2.17197      375.2     17.0     16.8     5.7
   14   3   3   1  23.147  46.293  1.95958      101.6      4.6      4.5     5.7
   15   4   3   0  23.279  46.557  1.94908      495.0     22.5     22.0     5.7
   16   0   0   2  24.415  48.83   1.86355      758.8     34.5     33.7     5.7
   17   2   5   0  24.911  49.822  1.82875      243.7     11.1     10.8     5.7
   18   0   2   2  26.218  52.436  1.74354       27.7      1.3      1.2     5.8
   19   2   0   2  26.293  52.585  1.73895       75.2      3.4      3.3     5.8
   20   3   4   1  26.356  52.712  1.73507      203.1      9.2      9.0     5.8
   21   1   5   1  26.644  53.288  1.71765       34.8      1.6      1.5     5.8
   22   5   1   1  27.085  54.169  1.69179       30.5      1.4      1.3     5.8
   23   0   6   0  27.9    55.8    1.64615      263.7     12.0     11.6     5.8
   24   2   2   2  28.009  56.019  1.64023       25.3      1.2      1.1     5.8
   25   5   2   1  28.354  56.708  1.62191      340.6     15.5     15.0     5.8
   26   6   0   0  28.539  57.078  1.61228       36.5      1.7      1.6     5.8
   27   6   1   0  28.952  57.905  1.59122       86.7      3.9      3.8     5.8
   28   2   6   0  29.623  59.245  1.55837       71.8      3.3      3.1     5.8
   29   2   3   2  30.063  60.126  1.53764      431.9     19.6     18.9     5.8
   30   3   5   1  30.121  60.242  1.53496      170.9      7.8      7.5     5.8
   31   5   3   1  30.393  60.786  1.52252      394.3     17.9     17.2     5.8
   32   1   6   1  31.178  62.356  1.4879       101.8      4.6      4.4     5.8
   33   4   0   2  31.454  62.909  1.47614       48.9      2.2      2.1     5.9
   34   6   3   0  32.139  64.277  1.44798       41.1      1.9      1.8     5.9
   35   2   4   2  32.805  65.61   1.42176       96.9      4.4      4.2     5.9
   36   4   2   2  33.0    65.999  1.41431      146.3      6.6      6.3     5.9
   37   5   4   1  33.119  66.239  1.40978       55.0      2.5      2.4     5.9
   38   3   6   1  34.372  68.744  1.36438       92.8      4.2      4.0     5.9
   39   2   7   0  34.658  69.315  1.35453       50.8      2.3      2.2     5.9
   40   4   3   2  34.881  69.761  1.34695      213.9      9.7      9.2     5.9
   41   1   7   1  36.095  72.191  1.30748       48.5      2.2      2.1     5.9
   42   2   5   2  36.167  72.334  1.30525      119.6      5.4      5.1     5.9
   43   7   0   1  36.475  72.949  1.29575       39.9      1.8      1.7     6.0
   44   7   1   1  36.838  73.677  1.28474      104.3      4.7      4.5     6.0
   45   7   2   1  37.922  75.844  1.25333      141.1      6.4      6.0     6.0
   46   6   5   0  38.075  76.149  1.24906       38.5      1.7      1.6     6.0
   47   0   6   2  38.634  77.268  1.23374      156.7      7.1      6.7     6.0
   48   1   0   3  38.69   77.379  1.23225       57.1      2.6      2.4     6.0
   49   6   0   2  39.179  78.358  1.21929       27.6      1.3      1.2     6.0
   50   6   1   2  39.534  79.069  1.2101        59.0      2.7      2.5     6.0
   51   2   6   2  40.116  80.232  1.19546       52.4      2.4      2.2     6.0
   52   8   2   0  40.982  81.965  1.17452       24.9      1.1      1.0     6.1
   53   3   0   3  41.639  83.278  1.1593        30.6      1.4      1.3     6.1
   54   1   3   3  41.871  83.741  1.15406       37.9      1.7      1.6     6.1
   55   6   3   2  42.352  84.703  1.1434        31.9      1.4      1.3     6.1
   56   4   8   0  44.467  88.934  1.09961       59.3      2.7      2.4     6.2
   57   2   7   2  44.67   89.339  1.09567       45.0      2.0      1.9     6.2

Reference:
Chichagov A.V. et al.
Information-Calculating System on Crystal Structure Data of Minerals
(MINCRYST)
- Kristallographiya, v.35, n.3, 1990, p.610-616 (in Russian)