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       ***
                  ***********************
BARIOPYROCHLORE

1, t-pyrochlore, f-microlite, s-microlite, DN

BaNb(2)O(6).H(2)O


Cubic  F d3m  Z = 8

Fd3m

19 .6 .1996

Ref.Str.:

         Perrault G. (1968)

         * Canad. Mineral., 9, 383-402

Ref.Composition & Lattice:

         Povarenniyh A.S. (1966)

         * Kristallohim. klassif. miner. vidov (in Russia)

Reserv:

         Pandaite.

         Ba(2-x)Nb(2)O(7-x)[H(2)O](x)

         The coordinates of atoms are from pyrochlore. N.A.D.

                   Initial data from BDM-file 

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

             a =  10.56     alpha =   90.0 
             b =  10.56     beta  =   90.0 
             c =  10.56     gamma =   90.0 

    Unit cell volume (cub. angs.) =  1177.58

    Molar volume ( cub.cm/mol.) =    88.66

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

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

   1 0.625   0.625   0.625    0.0    Nb    = 1.00
   2 0.125   0.125   0.125    0.0    Ba    = 0.97, Sr    = 0.03
   3 0.0     0.0     0.0      0.0    H(2)O = 1.00
   4 0.316   0.0     0.0      0.0    O     = 1.00


  Co-ordinates for all atomic positions :

   No       NoP      x/a        y/b       z/c 

     1       1     0.625      0.625      0.625 
     2       2     0.125      0.125      0.125 
     3       3     0.0        0.0        0.0   
     4       4     0.316      0.0        0.0   
     5       1     0.125      0.375      0.875 
     6       1     0.375      0.875      0.125 
     7       1     0.875      0.125      0.375 
     8       2     0.625      0.875      0.375 
     9       2     0.875      0.375      0.625 
    10       2     0.375      0.625      0.875 
    11       3     0.75       0.75       0.25  
    12       3     0.0        0.5        0.5   
    13       3     0.25       0.75       0.75  
    14       4     0.75       0.066      0.25  
    15       4     0.684      0.5        0.5   
    16       4     0.25       0.434      0.75  
    17       1     0.125      0.875      0.375 
    18       1     0.875      0.375      0.125 
    19       1     0.375      0.125      0.875 
    20       2     0.625      0.375      0.875 
    21       2     0.375      0.875      0.625 
    22       2     0.875      0.625      0.375 
    23       3     0.75       0.25       0.75  
    24       3     0.5        0.0        0.5   
    25       4     0.75       0.566      0.75  
    26       4     0.184      0.0        0.5   
    27       4     0.75       0.434      0.25  
    28       1     0.375      0.375      0.625 
    29       1     0.375      0.625      0.375 
    30       1     0.125      0.625      0.125 
    31       1     0.875      0.625      0.875 
    32       1     0.125      0.125      0.625 
    33       1     0.625      0.375      0.375 
    34       1     0.625      0.125      0.125 
    35       1     0.625      0.875      0.875 
    36       1     0.875      0.875      0.625 
    37       2     0.875      0.875      0.125 
    38       2     0.875      0.125      0.875 
    39       2     0.625      0.125      0.625 
    40       2     0.375      0.125      0.375 
    41       2     0.625      0.625      0.125 
    42       2     0.125      0.875      0.875 
    43       2     0.125      0.625      0.625 
    44       2     0.125      0.375      0.375 
    45       2     0.375      0.375      0.125 
    46       3     0.25       0.25       0.25  
    47       3     0.5        0.5        0.0   
    48       4     0.684      0.0        0.0   
    49       4     0.75       0.934      0.75  
    50       4     0.816      0.0        0.5   
    51       4     0.25       0.934      0.25  
    52       4     0.816      0.5        0.0   
    53       4     0.25       0.066      0.75  
    54       4     0.316      0.5        0.5   
    55       4     0.25       0.566      0.25  
    56       4     0.184      0.5        0.0   
    57       4     0.0        0.316      0.0   
    58       4     0.066      0.75       0.25  
    59       4     0.5        0.684      0.5   
    60       4     0.434      0.25       0.75  
    61       4     0.566      0.75       0.75  
    62       4     0.0        0.184      0.5   
    63       4     0.434      0.75       0.25  
    64       4     0.0        0.684      0.0   
    65       4     0.934      0.75       0.75  
    66       4     0.0        0.816      0.5   
    67       4     0.934      0.25       0.25  
    68       4     0.5        0.816      0.0   
    69       4     0.066      0.25       0.75  
    70       4     0.5        0.316      0.5   
    71       4     0.566      0.25       0.25  
    72       4     0.5        0.184      0.0   
    73       4     0.0        0.0        0.316 
    74       4     0.25       0.75       0.066 
    75       4     0.5        0.5        0.684 
    76       4     0.75       0.25       0.434 
    77       4     0.75       0.75       0.566 
    78       4     0.0        0.5        0.184 
    79       4     0.25       0.75       0.434 
    80       4     0.0        0.0        0.684 
    81       4     0.75       0.75       0.934 
    82       4     0.0        0.5        0.816 
    83       4     0.25       0.25       0.934 
    84       4     0.5        0.0        0.816 
    85       4     0.75       0.25       0.066 
    86       4     0.5        0.5        0.316 
    87       4     0.25       0.25       0.566 
    88       4     0.5        0.0        0.184 


X-ray density (g/cm cub.)   =      6.45

MU (1/cm) =    1334.363    Mass attenuation coefficient (cm**2/g) =    207.032

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

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

    1    Nb                  2.604        6
                                                 1.968        4
                                                 1.968        4
                                                 1.968        4
                                                 1.968        4
                                                 1.968        4
                                                 1.968        4
    2   Ba   ,Sr             3.456        8
                                                 2.2863       3
                                                 2.7483       4
                                                 2.2863       3
                                                 2.7483       4
                                                 2.7483       4
                                                 2.7483       4
                                                 2.7483       4
                                                 2.7483       4
    3    H(2)O               3.6          6
                                                 3.337        4
                                                 3.337        4
                                                 3.337        4
                                                 3.337        4
                                                 3.337        4
                                                 3.337        4
    4    O                   3.432        9
                                                 3.337        3
                                                 2.818        4
                                                 2.818        4
                                                 2.7479       4
                                                 2.7479       4
                                                 2.818        4
                                                 2.818        4
                                                 2.7479       4
                                                 2.7479       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   1   1   1  7.258  14.516   0.082  122.34    8       37.4       98.7
    2   2   2   0 11.906  23.813   0.134   44.11   12       16.2       10.0
    3   1   1   3 14.0    28.0     0.157   31.34   24       44.8      108.9
    4   2   2   2 14.636  29.273   0.164   28.5     8     1266.7    26386.8
    5   4   0   0 16.964  33.928   0.189   20.74    6      993.8     8860.3
    6   3   3   1 18.539  37.078   0.206   17.07   24      211.6     1323.3
    7   4   2   0 19.039  38.078   0.212   16.1    24        0.0        0.0
    8   2   2   4 20.937  41.875   0.232   13.03   24       77.2      134.5
    9   1   1   5 22.273  44.546   0.246   11.34   24      147.4      426.5
   10   3   3   3 22.273  44.546   0.246   11.34    8      104.4       71.3
   11   4   4   0 24.37   48.74    0.268    9.25   12     1180.3    11153.6
   12   5   3   1 25.565  51.13    0.28     8.3    48       86.3      213.7
   13   4   4   2 25.955  51.909   0.284    8.02   24        0.0        0.0
   14   6   2   0 27.473  54.946   0.299    7.04   24      107.4      140.6
   15   3   3   5 28.576  57.152   0.31     6.44   24        6.2        0.4
   16   2   2   6 28.937  57.874   0.314    6.26   24     1011.6    11088.2
   17   4   4   4 30.356  60.711   0.328    5.62    8      977.1     3097.6
   18   1   1   7 31.394  62.788   0.338    5.22   24       69.6       43.8
   19   5   5   1 31.394  62.788   0.338    5.22   24        3.7        0.1
   20   6   4   0 31.736  63.471   0.341    5.1    24        0.0        0.0
   21   6   4   2 33.083  66.166   0.354    4.66   48       29.7       14.2
   22   5   5   3 34.076  68.151   0.364    4.38   24       82.2       51.2
   23   7   3   1 34.076  68.151   0.364    4.38   48       21.2        6.8
   24   8   0   0 35.7    71.401   0.379    3.98    6     1003.0     1734.3
   25   3   3   7 36.66   73.32    0.388    3.78   24      162.8      173.6
   26   4   4   6 36.978  73.956   0.39     3.72   24        0.0        0.0
   27   8   2   0 36.978  73.956   0.39     3.72   24        0.0        0.0
   28   2   2   8 38.239  76.478   0.402    3.51   24       89.4       48.5
   29   6   6   0 38.239  76.478   0.402    3.51   12      150.4       68.6
   30   5   5   5 39.176  78.352   0.41     3.36    8      138.4       37.2
   31   7   5   1 39.176  78.352   0.41     3.36   48       85.0       84.1
   32   6   6   2 39.487  78.974   0.413    3.32   24      883.9     4491.3
   33   8   4   0 40.725  81.449   0.423    3.17   24      852.2     3982.9
   34   1   1   9 41.647  83.295   0.431    3.07   24       72.9       28.3
   35   7   5   3 41.647  83.295   0.431    3.07   48       90.6       87.3
   36   8   4   2 41.954  83.908   0.434    3.04   48        0.0        0.0
   37   6   6   4 43.178  86.356   0.444    2.94   24       87.1       38.6
   38   9   3   1 44.094  88.187   0.452    2.88   48       14.8        2.2


  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   2   2   2  14.636  29.273  3.04841    26386.8    100.0    100.0     5.6
    2   4   0   0  16.964  33.928  2.64        8860.3     33.6     33.4     5.7
    3   3   3   1  18.539  37.078  2.42263     1323.3      5.0      5.0     5.7
    4   1   1   5  22.273  44.546  2.03227      497.8      1.9      1.9     5.7
    5   4   4   0  24.37   48.74   1.86676    11153.6     42.3     41.5     5.7
    6   2   2   6  28.937  57.874  1.59198    11088.2     42.0     40.7     5.8
    7   4   4   4  30.356  60.711  1.5242      3097.6     11.7     11.3     5.8
    8   8   0   0  35.7    71.401  1.32        1734.3      6.6      6.2     5.9
    9   6   6   2  39.487  78.974  1.21132     4491.3     17.0     15.9     6.0
   10   8   4   0  40.725  81.449  1.18064     3982.9     15.1     14.0     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)