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       ***
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NATROTANTITE

1, syn

Na(2)Ta(4)O(11)


Hexagonal  R 3(-)c  Z = 6

R =0.087          NR =1565

25 .5 .1989

Ref.Str.:

         T.S. Ercit, F.C. Hawthorne, P. Cerny (1985)

         * Bull. Mineral., 108, 541-549

                   Initial data from BDM-file 

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

             a =   6.2092   alpha =   90.0 
             b =   6.2092   beta  =   90.0 
             c =  36.619    gamma =  120.0 

    Unit cell volume (cub. angs.) =  1222.67

    Molar volume ( cub.cm/mol.) =   122.74

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

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

   1 0.0     0.0     0.3323   3.1    Na    = 1.00
   2 0.3641  0.0     0.25     3.14   Ta    = 1.00
   3 0.0     0.0     0.0      3.36   Ta    = 1.00
   4 0.052   0.414   0.1975   2.2    O     = 1.00
   5 0.75    0.0     0.25     3.6    O     = 1.00
   6 0.0     0.0     0.4074   1.8    O     = 1.00


  Co-ordinates for all atomic positions :

   No       NoP      x/a        y/b       z/c 

     1       1     0.0        0.0        0.3323
     2       2     0.3641     0.0        0.25  
     3       3     0.0        0.0        0.0   
     4       4     0.052      0.414      0.1975
     5       5     0.75       0.0        0.25  
     6       6     0.0        0.0        0.4074
     7       2     0.0        0.3641     0.25  
     8       2     0.6359     0.6359     0.25  
     9       4     0.586      0.638      0.1975
    10       4     0.362      0.948      0.1975
    11       5     0.0        0.75       0.25  
    12       5     0.25       0.25       0.25  
    13       1     0.6667     0.3333     0.6656
    14       1     0.3333     0.6667     0.999 
    15       2     0.6667     0.6974     0.5833
    16       2     0.9692     0.3026     0.9167
    17       3     0.6667     0.3333     0.3333
    18       3     0.3333     0.6667     0.6667
    19       4     0.2527     0.9713     0.5308
    20       4     0.6953     0.6147     0.8642
    21       5     0.6667     0.0833     0.5833
    22       5     0.5833     0.9167     0.9167
    23       6     0.6667     0.3333     0.7407
    24       6     0.3333     0.6667     0.0741
    25       2     0.3026     0.9692     0.5833
    26       2     0.6974     0.6667     0.9167
    27       2     0.0308     0.3333     0.5833
    28       2     0.3333     0.0307     0.9167
    29       4     0.0287     0.2813     0.5308
    30       4     0.3853     0.0807     0.8642
    31       4     0.7187     0.7473     0.5308
    32       4     0.9193     0.3047     0.8642
    33       5     0.9167     0.5833     0.5833
    34       5     0.0833     0.6667     0.9167
    35       5     0.4167     0.3333     0.5833
    36       5     0.3333     0.4166     0.9167
    37       1     0.0        0.0        0.8323
    38       2     0.3641     0.3641     0.75  
    39       3     0.0        0.0        0.5   
    40       4     0.052      0.638      0.6975
    41       5     0.75       0.75       0.75  
    42       6     0.0        0.0        0.9074
    43       2     0.0        0.6359     0.75  
    44       2     0.6359     0.0        0.75  
    45       4     0.586      0.948      0.6975
    46       4     0.362      0.414      0.6975
    47       5     0.0        0.25       0.75  
    48       5     0.25       0.0        0.75  
    49       1     0.6667     0.3333     0.1656
    50       1     0.3333     0.6667     0.499 
    51       2     0.6667     0.9692     0.0833
    52       2     0.9692     0.6667     0.4167
    53       3     0.6667     0.3333     0.8333
    54       3     0.3333     0.6667     0.1667
    55       4     0.2527     0.2813     0.0308
    56       4     0.6953     0.0807     0.3642
    57       5     0.6667     0.5833     0.0833
    58       5     0.5833     0.6667     0.4167
    59       6     0.6667     0.3333     0.2407
    60       6     0.3333     0.6667     0.5741
    61       2     0.3026     0.3333     0.0833
    62       2     0.6974     0.0308     0.4167
    63       2     0.0308     0.6974     0.0833
    64       2     0.3333     0.3026     0.4167
    65       4     0.0287     0.7473     0.0308
    66       4     0.3853     0.3047     0.3642
    67       4     0.7187     0.9713     0.0308
    68       4     0.9193     0.6147     0.3642
    69       5     0.9167     0.3333     0.0833
    70       5     0.0833     0.4167     0.4167
    71       5     0.4167     0.0833     0.0833
    72       5     0.3333     0.9167     0.4167
    73       1     0.0        0.0        0.6677
    74       4     0.948      0.586      0.8025
    75       6     0.0        0.0        0.5926
    76       4     0.414      0.362      0.8025
    77       4     0.638      0.052      0.8025
    78       1     0.3333     0.6667     0.3344
    79       1     0.6667     0.3333     0.001 
    80       4     0.7473     0.0287     0.4692
    81       4     0.3047     0.3853     0.1358
    82       6     0.3333     0.6667     0.2593
    83       6     0.6667     0.3333     0.9259
    84       4     0.9713     0.7187     0.4692
    85       4     0.6147     0.9193     0.1358
    86       4     0.2813     0.2527     0.4692
    87       4     0.0807     0.6953     0.1358
    88       1     0.0        0.0        0.1677
    89       4     0.948      0.362      0.3025
    90       6     0.0        0.0        0.0926
    91       4     0.414      0.052      0.3025
    92       4     0.638      0.586      0.3025
    93       1     0.3333     0.6667     0.8344
    94       1     0.6667     0.3333     0.501 
    95       4     0.7473     0.7187     0.9692
    96       4     0.3047     0.9193     0.6358
    97       6     0.3333     0.6667     0.7593
    98       6     0.6667     0.3333     0.4259
    99       4     0.9713     0.2527     0.9692
   100       4     0.6147     0.6953     0.6358
   101       4     0.2813     0.0287     0.9692
   102       4     0.0807     0.3853     0.6358


X-ray density (g/cm cub.)   =      7.7 

MU (1/cm) =    1006.513    Mass attenuation coefficient (cm**2/g) =    130.643

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

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

    1    Na                  2.808        7
                                                 2.7501       6
                                                 2.4776       4
                                                 2.4775       4
                                                 2.4775       4
                                                 2.6595       4
                                                 2.6596       4
                                                 2.6596       4
    2    Ta                  2.424        7
                                                 2.3961       5
                                                 1.9484       4
                                                 2.0028       5
                                                 2.0028       5
                                                 2.01         6
                                                 2.01         6
                                                 1.9484       4
    3    Ta                  2.424        6
                                                 2.0116       4
                                                 2.0117       4
                                                 2.0117       4
                                                 2.0116       4
                                                 2.0117       4
                                                 2.0117       4
    4    O                   3.264        9
                                                 3.0          5
                                                 2.8839       4
                                                 2.8839       4
                                                 2.9709       5
                                                 2.738        5
                                                 2.6987       6
                                                 2.8054       4
                                                 2.8087       6
                                                 2.8055       4
    5    O                   3.264       10
                                                 3.0          4
                                                 2.738        4
                                                 2.9709       4
                                                 2.6887       5
                                                 2.6887       5
                                                 2.3954       6
                                                 2.3953       6
                                                 2.7379       4
                                                 2.9709       4
                                                 3.0          4
    6    O                   3.264        9
                                                 2.699        4
                                                 2.3953       5
                                                 2.6989       4
                                                 2.6989       4
                                                 2.3953       5
                                                 2.3952       5
                                                 2.8087       4
                                                 2.8087       4
                                                 2.8087       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   0   6  7.251  14.501   0.082  122.6     2      739.2     8963.7
    2   1   0  -2  8.586  17.172   0.097   86.79    6      479.8     8018.8
    3   1   0   4  9.563  19.126   0.108   69.54    6      209.0     1218.6
    4   1   0  -8 12.767  25.535   0.143   38.09    6      219.7      738.0
    5   1   1   0 14.366  28.731   0.161   29.66    6       93.9      105.0
    6   0   0  12 14.621  29.241   0.164   28.57    2     1385.7     7339.2
    7   1   0  10 14.744  29.487   0.165   28.06    6      369.9     1541.4
    8   1   1   3 14.833  29.667   0.166   27.7    12      808.0    14517.0
    9   1   1   6 16.163  32.325   0.181   23.03   12      781.6    11293.2
   10   2   0   2 16.832  33.664   0.188   21.09    6       12.9        1.4
   11   2   0  -4 17.373  34.746   0.194   19.69    6      379.0     1135.0
   12   1   1   9 18.185  36.37    0.203   17.81   12      539.1     4156.0
   13   1   0 -14 19.116  38.232   0.213   15.96    6      237.9      362.5
   14   2   0   8 19.406  38.812   0.216   15.44    6      362.8      815.4
   15   1   1  12 20.729  41.457   0.23    13.33   12       19.0        3.9
   16   2   0 -10 20.819  41.639   0.231   13.2     6      166.0      146.0
   17   1   0  16 21.455  42.911   0.237   12.34    6       74.6       27.6
   18   0   0  18 22.249  44.498   0.246   11.37    2      687.9      720.0
   19   2   1   1 22.307  44.615   0.246   11.3    12      288.0      752.4
   20   2   1  -2 22.416  44.831   0.248   11.18   12      220.2      435.1
   21   2   1   4 22.844  45.688   0.252   10.71   12      132.4      150.6
   22   2   1  -5 23.161  46.322   0.255   10.38   12      298.4      742.2
   23   1   1  15 23.665  47.33    0.261    9.89   12      600.0     2857.8
   24   2   1   7 23.991  47.982   0.264    9.59   12      155.1      185.2
   25   2   0  14 24.259  48.517   0.267    9.35    6       57.0       12.2
   26   2   1  -8 24.499  48.997   0.269    9.14   12      197.4      285.9
   27   3   0   0 25.451  50.902   0.279    8.38    6     1059.2     3774.1
   28   2   1  10 25.687  51.374   0.281    8.21   12      249.2      409.2
   29   2   0 -16 26.231  52.461   0.287    7.83    6      344.2      372.1
   30   2   1 -11 26.362  52.724   0.288    7.74   12      147.7      135.5
   31   1   0 -20 26.386  52.772   0.288    7.72    6      126.9       49.9
   32   3   0  -6 26.608  53.217   0.291    7.57    6      338.5      348.4
   33   3   0   6 26.608  53.217   0.291    7.57    6      365.5      406.2
   34   1   1  18 26.916  53.831   0.294    7.38   12      653.1     2526.2
   35   2   1  13 27.862  55.724   0.303    6.82   12      230.4      290.7
   36   2   1 -14 28.683  57.365   0.312    6.39   12      196.9      198.8
   37   1   0  22 28.975  57.951   0.314    6.24    6      264.2      174.9
   38   2   2   0 29.75   59.5     0.322    5.88    6        0.2        0.0
   39   3   0 -12 29.893  59.787   0.324    5.82    6      816.3     1556.4
   40   3   0  12 29.893  59.787   0.324    5.82    6      797.8     1486.7
   41   2   2   3 30.014  60.028   0.325    5.77   12      470.8     1026.2
   42   0   0  24 30.321  60.641   0.328    5.64    2      897.9      608.1
   43   1   1  21 30.441  60.881   0.329    5.59   12      528.0     1250.5
   44   2   1  16 30.455  60.91    0.329    5.58   12      152.1      103.6
   45   2   0  20 30.596  61.192   0.33     5.53    6      353.1      276.5
   46   2   2   6 30.798  61.597   0.332    5.45   12      461.0      929.1
   47   3   1  -1 31.125  62.25    0.336    5.32   12      240.4      246.7
   48   3   1   2 31.211  62.422   0.336    5.29   12      352.6      527.8
   49   2   1 -17 31.404  62.808   0.338    5.22   12      186.3      145.4
   50   3   1  -4 31.553  63.106   0.34     5.16   12       18.9        1.5
   51   3   1   5 31.808  63.617   0.342    5.07   12      188.4      144.5
   52   2   2   9 32.08   64.16    0.345    4.98   12      398.9      636.0
   53   3   1  -7 32.484  64.967   0.349    4.85   12      169.5      111.8
   54   3   1   8 32.902  65.804   0.353    4.71   12       30.9        3.6
   55   2   0 -22 32.975  65.95    0.353    4.69    6       65.7        8.1
   56   2   1  19 33.421  66.842   0.358    4.56   12      205.2      154.1
   57   2   2  12 33.83   67.66    0.361    4.45   12       30.2        3.3
   58   3   1 -10 33.895  67.79    0.362    4.43   12      282.7      284.0
   59   1   1  24 34.23   68.46    0.365    4.34   12       41.0        5.9
   60   1   0 -26 34.427  68.854   0.367    4.29    6      155.5       41.6
   61   3   1  11 34.468  68.936   0.367    4.28   12      150.2       77.4
   62   2   1 -20 34.488  68.976   0.368    4.27   12      163.4       91.5
   63   3   0 -18 34.942  69.884   0.372    4.16    6      315.7      166.4
   64   3   0  18 34.942  69.884   0.372    4.16    6      308.8      159.2
   65   4   0  -2 35.066  70.133   0.373    4.13    6      341.1      192.8
   66   4   0   4 35.389  70.779   0.376    4.05    6       50.2        4.1
   67   3   1 -13 35.761  71.522   0.379    3.97   12      153.9       75.5
   68   2   2  15 36.018  72.036   0.382    3.92   12      375.3      442.8
   69   3   1  14 36.48   72.96    0.386    3.82   12      215.2      142.0
   70   4   0  -8 36.668  73.337   0.388    3.78    6       16.5        0.4
   71   2   1  22 36.738  73.476   0.388    3.77   12      186.2      104.9
   72   1   0  28 37.312  74.623   0.393    3.66    6       92.9       12.7
   73   4   0  10 37.617  75.233   0.396    3.61    6      245.4       87.2
   74   2   1 -23 37.921  75.842   0.399    3.56   12      179.8       92.4
   75   3   1 -16 38.058  76.116   0.4      3.53   12       34.4        3.3
   76   2   0  26 38.127  76.254   0.401    3.52    6        6.7        0.1
   77   1   1  27 38.3    76.599   0.402    3.5    12      311.6      272.4
   78   2   2  18 38.622  77.243   0.405    3.45   12      384.7      409.3
   79   3   2   1 38.664  77.328   0.406    3.44   12       85.4       20.1
   80   3   2  -2 38.742  77.483   0.406    3.43   12       54.6        8.2
   81   3   1  17 38.917  77.834   0.408    3.4    12      177.9       86.4
   82   3   2   4 39.053  78.106   0.409    3.38   12      258.7      181.7
   83   0   0  30 39.128  78.255   0.41     3.37    2      220.5       21.9
   84   3   2  -5 39.286  78.572   0.411    3.35   12      129.9       45.4
   85   3   2   7 39.905  79.811   0.416    3.27   12       45.7        5.5
   86   4   0 -14 40.108  80.216   0.418    3.24    6      159.1       33.0
   87   3   2  -8 40.291  80.583   0.42     3.22   12      245.9      156.3
   88   2   1  25 40.407  80.814   0.421    3.21   12       92.0       21.8
   89   3   1 -19 40.773  81.545   0.424    3.16   12      170.3       73.6
   90   2   0 -28 40.917  81.833   0.425    3.15    6      164.9       34.3
   91   4   1   0 41.029  82.057   0.426    3.14   12       42.8        4.6
   92   3   2  10 41.214  82.428   0.428    3.12   12       16.6        0.7
   93   4   1  -3 41.259  82.518   0.428    3.11   12      252.4      159.1
   94   4   1   3 41.259  82.518   0.428    3.11   12      280.4      196.4
   95   3   0 -24 41.527  83.055   0.43     3.08    6      530.3      348.0
   96   3   0  24 41.527  83.055   0.43     3.08    6      545.9      368.8
   97   2   2  21 41.633  83.265   0.431    3.07   12      318.0      249.5
   98   4   0  16 41.645  83.291   0.431    3.07    6       62.7        4.8
   99   2   1 -26 41.712  83.425   0.432    3.07   12       78.9       15.3
  100   3   2 -11 41.751  83.501   0.432    3.06   12       51.3        6.5
  101   3   1  20 41.77   83.539   0.432    3.06   12        1.9        0.0
  102   4   1  -6 41.948  83.896   0.434    3.04   12      284.5      197.8
  103   4   1   6 41.948  83.896   0.434    3.04   12      301.2      221.6
  104   1   1  30 42.693  85.386   0.44     2.98   12      336.1      270.0
  105   3   2  13 42.973  85.945   0.442    2.96   12      106.4       26.9
  106   4   1  -9 43.093  86.187   0.443    2.95   12      240.4      136.7
  107   4   1   9 43.093  86.187   0.443    2.95   12      245.7      142.9
  108   1   0 -32 43.487  86.974   0.447    2.92    6      105.4       13.0
  109   3   2 -14 43.658  87.317   0.448    2.91   12       27.0        1.7
  110   3   1 -22 43.906  87.812   0.45     2.89   12      216.1      108.4
  111   2   1  28 44.458  88.915   0.455    2.86   12       80.9       15.0
  112   4   1 -12 44.692  89.384   0.457    2.84   12       17.3        0.7
  113   4   1  12 44.692  89.384   0.457    2.84   12       29.3        2.0


  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   0   6   7.251  14.501  6.10317     8963.7     61.7     62.4     5.6
    2   1   0   2   8.586  17.172  5.15942     8018.8     55.2     55.7     5.6
    3   1   0   4   9.563  19.126  4.63663     1218.6      8.4      8.5     5.6
    4   1   0   8  12.767  25.535  3.48555      738.0      5.1      5.1     5.6
    5   0   0  12  14.621  29.241  3.05158     7339.2     50.6     50.6     5.6
    6   1   0  10  14.744  29.487  3.02673     1541.4     10.6     10.6     5.6
    7   1   1   3  14.833  29.667  3.0088     14517.0    100.0    100.0     5.6
    8   1   1   6  16.163  32.325  2.76716    11293.2     77.8     77.6     5.6
    9   2   0   4  17.373  34.746  2.57971     1135.0      7.8      7.8     5.7
   10   1   1   9  18.185  36.37   2.46816     4156.0     28.6     28.5     5.7
   11   1   0  14  19.116  38.232  2.35214      362.5      2.5      2.5     5.7
   12   2   0   8  19.406  38.812  2.31832      815.4      5.6      5.6     5.7
   13   2   0  10  20.819  41.639  2.16723      146.0      1.0      1.0     5.7
   14   0   0  18  22.249  44.498  2.03439      720.0      5.0      4.9     5.7
   15   2   1   1  22.307  44.615  2.02931      752.4      5.2      5.1     5.7
   16   2   1   2  22.416  44.831  2.02003      435.1      3.0      3.0     5.7
   17   2   1   4  22.844  45.688  1.98413      150.6      1.0      1.0     5.7
   18   2   1   5  23.161  46.322  1.95842      742.2      5.1      5.0     5.7
   19   1   1  15  23.665  47.33   1.91903     2857.8     19.7     19.3     5.7
   20   2   1   7  23.991  47.982  1.89448      185.2      1.3      1.3     5.7
   21   2   1   8  24.499  48.997  1.85756      285.9      2.0      1.9     5.7
   22   3   0   0  25.451  50.902  1.79244     3774.1     26.0     25.4     5.8
   23   2   1  10  25.687  51.374  1.77707      409.2      2.8      2.8     5.8
   24   2   0  16  26.231  52.461  1.74278      372.1      2.6      2.5     5.8
   25   2   1  11  26.362  52.724  1.73469      185.5      1.3      1.2     5.8
   26   3   0   6  26.608  53.217  1.71981      754.5      5.2      5.1     5.8
   27   1   1  18  26.916  53.831  1.7016      2526.2     17.4     17.0     5.8
   28   2   1  13  27.862  55.724  1.6482       290.7      2.0      1.9     5.8
   29   2   1  14  28.683  57.365  1.60489      198.8      1.4      1.3     5.8
   30   1   0  22  28.975  57.951  1.59007      174.9      1.2      1.2     5.8
   31   3   0  12  29.893  59.787  1.54554     3043.1     21.0     20.3     5.8
   32   2   2   3  30.014  60.028  1.5399      1026.2      7.1      6.8     5.8
   33   0   0  24  30.321  60.641  1.52579      608.1      4.2      4.0     5.8
   34   1   1  21  30.441  60.881  1.52036     1354.1      9.3      9.0     5.8
   35   2   0  20  30.596  61.192  1.51336      276.5      1.9      1.8     5.8
   36   2   2   6  30.798  61.597  1.5044       929.1      6.4      6.2     5.8
   37   3   1   1  31.125  62.25   1.49017      246.7      1.7      1.6     5.8
   38   3   1   2  31.211  62.422  1.48648      527.8      3.6      3.5     5.8
   39   2   1  17  31.404  62.808  1.47828      145.4      1.0      1.0     5.9
   40   2   2   9  32.08   64.16   1.45033      636.0      4.4      4.2     5.9
   41   2   1  19  33.421  66.842  1.3985       154.1      1.1      1.0     5.9
   42   3   1  10  33.895  67.79   1.38124      284.0      2.0      1.9     5.9
   43   2   1  20  34.488  68.976  1.36035      168.9      1.2      1.1     5.9
   44   3   0  18  34.942  69.884  1.3449       325.6      2.2      2.1     5.9
   45   4   0   2  35.066  70.133  1.34072      192.8      1.3      1.3     5.9
   46   2   2  15  36.018  72.036  1.30992      442.8      3.0      2.9     5.9
   47   1   1  27  38.3    76.599  1.24284      272.4      1.9      1.8     6.0
   48   2   2  18  38.622  77.243  1.23408      409.3      2.8      2.6     6.0
   49   3   2   4  39.053  78.106  1.22259      181.7      1.3      1.2     6.0
   50   3   2   8  40.291  80.583  1.19114      156.3      1.1      1.0     6.1
   51   4   1   3  41.259  82.518  1.16804      355.5      2.4      2.3     6.1
   52   3   0  24  41.527  83.055  1.16185      716.8      4.9      4.6     6.1
   53   2   2  21  41.633  83.265  1.15945      254.4      1.8      1.6     6.1
   54   4   1   6  41.948  83.896  1.15232      419.4      2.9      2.7     6.1
   55   1   1  30  42.693  85.386  1.13599      270.0      1.9      1.7     6.1
   56   4   1   9  43.093  86.187  1.12748      279.5      1.9      1.8     6.1

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)