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       ***
                  ***********************
WEBERITE

2, analogue, t-weberite

Sr(2)Sb(2)O(7)


Orthorhombic  I mma  Z = 4

R =0.0348          NR =85

1 .4 .1993

Ref.Str.:

         Groen W.A., Ijdo D.J.W. (1988)

         * Acta Cryst., C 44, 782-784

Reserv:

         Neutron  powder diffraction data. Rietveld method.   D.T.N.

                   Initial data from BDM-file 

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

             a =   7.4557   alpha =   90.0 
             b =  10.3708   beta  =   90.0 
             c =   7.686    gamma =   90.0 

    Unit cell volume (cub. angs.) =   594.29

    Molar volume ( cub.cm/mol.) =    89.49

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

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

   1 0.0     0.0     0.0      0.42   Sr    = 1.00
   2 0.25    0.25    0.75     0.59   Sr    = 1.00
   3 0.25    0.25    0.25     0.01   Sb    = 1.00
   4 0.0     0.0     0.5      0.18   Sb    = 1.00
   5 0.0     0.25    0.1538   0.32   O     = 1.00
   6 0.0     0.4092  0.718    0.31   O     = 1.00
   7 0.202   0.3809  0.4299   0.32   O     = 1.00


  Co-ordinates for all atomic positions :

   No       NoP      x/a        y/b       z/c 

     1       1     0.0        0.0        0.0   
     2       2     0.25       0.25       0.75  
     3       3     0.25       0.25       0.25  
     4       4     0.0        0.0        0.5   
     5       5     0.0        0.25       0.1538
     6       6     0.0        0.4092     0.718 
     7       7     0.202      0.3809     0.4299
     8       1     0.5        0.0        0.5   
     9       2     0.25       0.75       0.25  
    10       3     0.25       0.75       0.75  
    11       4     0.5        0.0        0.0   
    12       5     0.5        0.75       0.6538
    13       6     0.5        0.5908     0.218 
    14       7     0.298      0.6191     0.9299
    15       2     0.75       0.25       0.75  
    16       3     0.75       0.25       0.25  
    17       7     0.798      0.3809     0.4299
    18       2     0.75       0.75       0.25  
    19       3     0.75       0.75       0.75  
    20       7     0.702      0.6191     0.9299
    21       5     0.5        0.25       0.3462
    22       6     0.5        0.4092     0.782 
    23       7     0.702      0.3809     0.0701
    24       5     0.0        0.75       0.8462
    25       6     0.0        0.5908     0.282 
    26       7     0.798      0.6191     0.5701
    27       7     0.298      0.3809     0.0701
    28       7     0.202      0.6191     0.5701
    29       1     0.0        0.5        0.0   
    30       4     0.0        0.5        0.5   
    31       6     0.0        0.0908     0.718 
    32       7     0.798      0.1191     0.4299
    33       1     0.5        0.5        0.5   
    34       4     0.5        0.5        0.0   
    35       6     0.5        0.9092     0.218 
    36       7     0.702      0.8809     0.9299
    37       7     0.202      0.1191     0.4299
    38       7     0.298      0.8809     0.9299
    39       6     0.5        0.0908     0.782 
    40       7     0.298      0.1191     0.0701
    41       6     0.0        0.9092     0.282 
    42       7     0.202      0.8809     0.5701
    43       7     0.702      0.1191     0.0701
    44       7     0.798      0.8809     0.5701


X-ray density (g/cm cub.)   =      5.93

MU (1/cm) =     993.697    Mass attenuation coefficient (cm**2/g) =    167.576

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

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

    1    Sr                  3.072        8
                                                 2.8495       5
                                                 2.8495       5
                                                 2.3632       6
                                                 2.5985       7
                                                 2.5985       7
                                                 2.5985       7
                                                 2.3632       6
                                                 2.5985       7
    2    Sr                  3.072        8
                                                 2.5021       6
                                                 2.8327       7
                                                 2.5021       6
                                                 2.8327       7
                                                 2.5021       6
                                                 2.8327       7
                                                 2.5021       6
                                                 2.8327       7
    3    Sb                  2.712        6
                                                 2.0052       5
                                                 1.9705       7
                                                 2.0052       5
                                                 1.9705       7
                                                 1.9705       7
                                                 1.9705       7
    4    Sb                  2.712        6
                                                 1.922        6
                                                 2.0209       7
                                                 2.0209       7
                                                 1.922        6
                                                 2.0209       7
                                                 2.0209       7
    5    O                   3.264        8
                                                 2.935        7
                                                 2.935        7
                                                 2.682        7
                                                 2.682        7
                                                 2.935        7
                                                 2.935        7
                                                 2.682        7
                                                 2.682        7
    6    O                   3.264        4
                                                 2.694        7
                                                 2.694        7
                                                 2.8808       7
                                                 2.8808       7
    7    O                   3.264        8
                                                 2.935        5
                                                 2.694        6
                                                 3.0121       7
                                                 2.682        5
                                                 2.8808       6
                                                 2.8565       7
                                                 2.6951       7
                                                 2.7151       7

  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   1   1  7.166  14.332   0.081  125.57    4       81.2      937.8
    2   1   0   1  8.276  16.551   0.093   93.59    4       79.3      665.9
    3   0   2   0  8.543  17.086   0.096   87.7     2        3.7        0.7
    4   0   0   2 11.563  23.125   0.13    46.89    2        9.4        2.4
    5   2   0   0 11.925  23.85    0.134   43.96    2        8.1        1.6
    6   1   2   1 11.937  23.875   0.134   43.87    8       72.1      516.1
    7   1   1   2 13.734  27.468   0.154   32.64    8       18.8       26.2
    8   2   1   1 13.967  27.934   0.157   31.5     8       80.0      456.6
    9   0   3   1 14.142  28.284   0.159   30.67    4       85.8      255.7
   10   0   2   2 14.447  28.894   0.162   29.31    4      584.4    11337.7
   11   2   2   0 14.743  29.486   0.165   28.07    4      577.0    10580.9
   12   2   0   2 16.731  33.461   0.187   21.37    4      467.9     5298.2
   13   0   4   0 17.283  34.566   0.193   19.91    2      465.1     2439.1
   14   0   1   3 18.041  36.082   0.201   18.13    4       36.8       27.7
   15   1   3   2 18.482  36.965   0.206   17.19    8       19.3       14.5
   16   1   0   3 18.537  37.073   0.206   17.08    4       48.0       44.5
   17   2   3   1 18.662  37.324   0.208   16.83    8       37.3       53.2
   18   2   2   2 18.901  37.803   0.21    16.36    8       12.7        6.0
   19   3   0   1 19.011  38.021   0.211   16.15    4       20.3        7.5
   20   1   4   1 19.276  38.553   0.214   15.67    8        4.2        0.6
   21   1   2   3 20.543  41.085   0.228   13.6     8       14.8        6.8
   22   3   2   1 20.978  41.957   0.232   12.98    8       54.3       86.8
   23   0   4   2 21.001  42.002   0.233   12.95    4       34.1       17.1
   24   2   4   0 21.216  42.432   0.235   12.65    4       58.7       49.4
   25   2   1   3 21.857  43.715   0.242   11.83    8       25.5       17.4
   26   0   3   3 21.976  43.953   0.243   11.69    4      132.1      230.9
   27   3   1   2 22.117  44.235   0.244   11.52    8       58.4       89.0
   28   0   5   1 22.622  45.245   0.25    10.95    4       32.3       13.0
   29   0   0   4 23.633  47.266   0.26     9.92    2      503.5     1424.2
   30   4   0   0 24.41   48.819   0.268    9.22    2      578.5     1747.1
   31   2   4   2 24.437  48.873   0.269    9.19    8      551.3     6329.7
   32   1   1   4 24.871  49.743   0.273    8.83    8       39.4       31.1
   33   2   3   3 25.308  50.615   0.277    8.49    8       64.1       78.9
   34   0   2   4 25.31   50.62    0.278    8.49    4       21.5        4.4
   35   3   3   2 25.54   51.081   0.28     8.32    8       29.9       16.8
   36   4   1   1 25.574  51.148   0.28     8.29    8       47.9       43.1
   37   3   0   3 25.582  51.165   0.28     8.28    4       25.4        6.1
   38   1   5   2 25.752  51.503   0.282    8.16    8       28.7       15.2
   39   1   4   3 25.793  51.586   0.282    8.13    8       65.8       79.7
   40   2   5   1 25.89   51.779   0.283    8.06    8       26.8       13.1
   41   4   2   0 26.049  52.099   0.285    7.95    4        1.6        0.0
   42   3   4   1 26.16   52.32    0.286    7.87    8       74.8       99.8
   43   0   6   0 26.465  52.929   0.289    7.67    2       64.1       17.8
   44   2   0   4 26.807  53.615   0.293    7.45    4       20.2        3.5
   45   3   2   3 27.171  54.342   0.296    7.22    8       16.4        4.4
   46   4   0   2 27.342  54.684   0.298    7.12    4       21.5        3.7
   47   1   6   1 27.925  55.85    0.304    6.79    8       39.7       24.3
   48   1   3   4 28.043  56.086   0.305    6.72    8       26.5       10.7
   49   2   2   4 28.348  56.696   0.308    6.56    8      489.5     3559.3
   50   0   5   3 28.543  57.086   0.31     6.46    4       67.1       32.9
   51   4   3   1 28.69   57.381   0.312    6.38    8       79.5       91.4
   52   4   2   2 28.863  57.727   0.313    6.3     8      458.8     3002.0
   53   0   6   2 29.252  58.503   0.317    6.11    4      484.9     1627.4
   54   2   6   0 29.421  58.841   0.319    6.03    4      426.8     1244.3
   55   0   4   4 29.932  59.863   0.324    5.8     4      442.8     1288.7
   56   0   1   5 30.435  60.871   0.329    5.59    4       52.8       17.6
   57   4   4   0 30.595  61.19    0.33     5.53    4      426.5     1138.6
   58   1   0   5 30.773  61.545   0.332    5.46    4       51.9       16.6
   59   3   1   4 30.806  61.612   0.332    5.44    8        9.5        1.1
   60   4   1   3 31.093  62.185   0.335    5.33    8       13.9        2.3
   61   2   5   3 31.371  62.742   0.338    5.23    8       79.0       73.9
   62   3   5   2 31.574  63.148   0.34     5.15    8        3.0        0.1
   63   3   4   3 31.61   63.221   0.34     5.14    8       73.9       63.5
   64   5   0   1 31.749  63.499   0.342    5.09    4       87.1       43.8
   65   0   7   1 31.971  63.942   0.344    5.02    4       54.7       17.0
   66   2   6   2 32.042  64.083   0.344    4.99    8       35.1       13.9
   67   1   2   5 32.192  64.384   0.346    4.94    8       49.4       27.3
   68   2   4   4 32.688  65.375   0.351    4.78    8       31.8       10.9
   69   5   2   1 33.146  66.291   0.355    4.64    8       51.7       28.1
   70   4   4   2 33.162  66.325   0.355    4.64    8        1.5        0.0
   71   2   1   5 33.168  66.335   0.355    4.63    8       88.2       81.7
   72   1   6   3 33.19   66.38    0.355    4.63    8       39.0       16.0
   73   0   3   5 33.257  66.515   0.356    4.61    4       10.2        0.5
   74   3   6   1 33.504  67.009   0.358    4.54    8       48.9       24.6
   75   3   3   4 33.611  67.221   0.359    4.51    8       21.8        4.8
   76   1   5   4 33.789  67.578   0.361    4.46    8        5.4        0.3
   77   4   3   3 33.884  67.768   0.362    4.43    8       75.1       56.7
   78   5   1   2 33.99   67.98    0.363    4.4     8        9.6        0.9
   79   4   5   1 34.373  68.745   0.366    4.3     8       41.6       16.9
   80   1   7   2 34.521  69.043   0.368    4.26    8        9.4        0.9
   81   2   7   1 34.637  69.274   0.369    4.23    8       66.5       42.4
   82   4   0   4 35.152  70.304   0.374    4.11    4      425.7      843.4
   83   2   3   5 35.876  71.753   0.38     3.95    8       15.7        2.2
   84   3   0   5 36.1    72.201   0.382    3.9     4       79.1       27.6
   85   1   4   5 36.273  72.546   0.384    3.86    8       30.5        8.1
   86   0   8   0 36.455  72.91    0.386    3.83    2      468.1      474.7
   87   4   2   4 36.484  72.968   0.386    3.82    8       14.9        1.9
   88   5   3   2 36.671  73.342   0.388    3.78    8       31.0        8.2
   89   5   0   3 36.705  73.41    0.388    3.78    4       46.6        9.3
   90   0   6   4 36.828  73.656   0.389    3.75    4        6.0        0.2
   91   0   7   3 36.912  73.824   0.39     3.74    4       16.0        1.1
   92   0   0   6 36.964  73.928   0.39     3.73    2       41.0        3.6
   93   5   4   1 37.177  74.354   0.392    3.69    8       15.8        2.1
   94   3   2   5 37.419  74.838   0.394    3.64    8       47.8       18.9
   95   4   6   0 37.428  74.856   0.395    3.64    4       39.3        6.4
   96   1   8   1 37.689  75.378   0.397    3.6     8       41.0       13.7
   97   1   1   6 37.925  75.85    0.399    3.56    8        1.8        0.0
   98   5   2   3 38.016  76.032   0.4      3.54    8       20.2        3.3
   99   0   2   6 38.271  76.543   0.402    3.5     4      385.8      590.0
  100   6   0   0 38.308  76.616   0.402    3.49    2       44.5        3.9
  101   3   6   3 38.355  76.71    0.403    3.49    8       39.4       12.3
  102   0   5   5 38.587  77.175   0.405    3.45    4        5.8        0.1
  103   0   8   2 38.836  77.671   0.407    3.41    4       25.7        2.6
  104   3   5   4 38.92   77.84    0.408    3.4     8       32.0        7.9
  105   2   8   0 38.983  77.967   0.408    3.39    4       28.8        3.2
  106   4   5   3 39.178  78.357   0.41     3.36    8       42.1       13.5
  107   6   1   1 39.221  78.442   0.41     3.36    8       40.9       12.7
  108   2   6   4 39.348  78.696   0.412    3.34    8      388.3     1141.0
  109   2   7   3 39.43   78.861   0.412    3.33    8       27.0        5.5
  110   2   0   6 39.481  78.962   0.413    3.32    4      430.0      695.7
  111   6   2   0 39.601  79.202   0.414    3.31    4      394.0      581.3
  112   3   7   2 39.614  79.229   0.414    3.3     8       40.4       12.2
  113   4   6   2 39.789  79.578   0.415    3.28    8      415.4     1282.6
  114   4   4   4 40.382  80.764   0.421    3.21    8      375.7     1025.5
  115   1   3   6 40.507  81.013   0.422    3.19    8       20.4        3.0
  116   6   0   2 40.654  81.307   0.423    3.18    4      372.1      498.1
  117   2   2   6 40.764  81.528   0.424    3.16    8       11.6        1.0
  118   4   1   5 40.825  81.65    0.424    3.16    8       32.4        7.5
  119   2   5   5 41.075  82.149   0.426    3.13    8       38.7       10.6
  120   5   1   4 41.153  82.306   0.427    3.12    8       44.1       13.7
  121   3   4   5 41.29   82.579   0.428    3.11    8        2.1        0.0
  122   2   8   2 41.319  82.638   0.429    3.1     8      363.6      929.9
  123   1   7   4 41.651  83.303   0.431    3.07    8       29.2        5.9
  124   6   3   1 41.782  83.564   0.433    3.06    8       14.8        1.5
  125   5   5   2 41.839  83.677   0.433    3.05    8       30.5        6.5
  126   5   4   3 41.871  83.743   0.433    3.05    8       42.3       12.4
  127   6   2   2 41.929  83.858   0.434    3.04    8        5.1        0.2
  128   0   4   6 42.121  84.243   0.435    3.03    4       49.3        8.3
  129   4   7   1 42.196  84.392   0.436    3.02    8       39.2       10.5
  130   1   8   3 42.368  84.736   0.437    3.01    8       49.1       16.4
  131   0   9   1 42.527  85.054   0.439    2.99    4       75.3       19.2
  132   3   8   1 42.658  85.316   0.44     2.98    8        0.4        0.0
  133   1   6   5 42.727  85.454   0.44     2.98    8       20.3        2.8
  134   3   1   6 42.887  85.774   0.442    2.96    8       16.1        1.7
  135   4   3   5 43.368  86.735   0.446    2.93    8       31.9        6.7
  136   6   4   0 43.425  86.85    0.446    2.92    4       13.9        0.6
  137   5   6   1 43.595  87.19    0.448    2.91    8       27.7        5.1
  138   5   3   4 43.693  87.386   0.448    2.9     8       38.7        9.8
  139   6   1   3 43.863  87.727   0.45     2.89    8       57.9       21.9
  140   2   4   6 44.572  89.145   0.456    2.85    8      355.0      813.8
  141   0   1   7 44.866  89.732   0.458    2.84    4       32.1        3.3
  142   1   9   2 44.868  89.736   0.458    2.84    8        1.8        0.0
  143   2   9   1 44.976  89.952   0.459    2.83    8       20.3        2.6


  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   1   1   7.166  14.332  6.17502      937.8      8.3      8.4     5.6
    2   1   0   1   8.276  16.551  5.35154      665.9      5.9      5.9     5.6
    3   1   2   1  11.937  23.875  3.72398      517.7      4.6      4.6     5.6
    4   2   1   1  13.967  27.934  3.19139      456.6      4.0      4.0     5.6
    5   0   3   1  14.142  28.284  3.15272      255.7      2.3      2.3     5.6
    6   0   2   2  14.447  28.894  3.08751    11337.7    100.0    100.0     5.6
    7   2   2   0  14.743  29.486  3.02684    10580.9     93.3     93.3     5.6
    8   2   0   2  16.731  33.461  2.67577     5298.2     46.7     46.6     5.7
    9   0   4   0  17.283  34.566  2.5927      2439.1     21.5     21.4     5.7
   10   0   3   3  21.976  43.953  2.05834      230.9      2.0      2.0     5.7
   11   0   0   4  23.633  47.266  1.9215      1424.2     12.6     12.3     5.7
   12   2   4   2  24.437  48.873  1.86199     8076.8     71.2     69.8     5.7
   13   2   2   4  28.348  56.696  1.62223     3559.3     31.4     30.5     5.8
   14   4   2   2  28.863  57.727  1.59569     3002.0     26.5     25.7     5.8
   15   0   6   2  29.252  58.503  1.57636     1627.4     14.4     13.9     5.8
   16   2   6   0  29.421  58.841  1.56811     1244.3     11.0     10.6     5.8
   17   0   4   4  29.932  59.863  1.54376     1288.7     11.4     11.0     5.8
   18   4   4   0  30.595  61.19   1.51342     1138.6     10.0      9.7     5.8
   19   2   1   5  33.168  66.335  1.40796      125.8      1.1      1.1     5.9
   20   4   0   4  35.152  70.304  1.33789      843.4      7.4      7.1     5.9
   21   0   8   0  36.455  72.91   1.29635      476.6      4.2      4.0     6.0
   22   0   2   6  38.271  76.543  1.24361      590.0      5.2      4.9     6.0
   23   2   6   4  39.348  78.696  1.2149      1141.0     10.1      9.4     6.0
   24   2   0   6  39.481  78.962  1.21147      695.7      6.1      5.7     6.0
   25   6   2   0  39.601  79.202  1.2084       593.5      5.2      4.9     6.0
   26   4   6   2  39.789  79.578  1.20363     1282.6     11.3     10.5     6.0
   27   4   4   4  40.382  80.764  1.18893     1025.5      9.0      8.4     6.1
   28   6   0   2  40.654  81.307  1.18234      498.1      4.4      4.1     6.1
   29   2   8   2  41.319  82.638  1.16664      929.9      8.2      7.6     6.1
   30   2   4   6  44.572  89.145  1.09756      813.8      7.2      6.5     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)