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       ***
                  ***********************
FORSTERITE

8, t-olivine, at 111 kbar, f-olivine, s-forsterite

Mg(2)SiO(4)


Orthorhombic  P bnm  Z = 4

R =0.071          NR =84

27 .9 .1991

Ref.Str.:

         Kudoh Y., Takeuchi Y. (1985)

         * Z. Kristallogr., 171, 291-302

                   Initial data from BDM-file 

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

             a =   4.668    alpha =   90.0 
             b =   9.852    beta  =   90.0 
             c =   5.836    gamma =   90.0 

    Unit cell volume (cub. angs.) =   268.39

    Molar volume ( cub.cm/mol.) =    40.42

  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      0.45   Mg    = 1.00
   2 0.9945  0.2741  0.25     0.2    Mg    = 1.00
   3 0.4316  0.0942  0.25     0.0    Si    = 1.00
   4 0.7715  0.0908  0.25     0.07   O     = 1.00
   5 0.2131  0.4506  0.25     0.12   O     = 1.00
   6 0.2862  0.1644  0.0322   0.22   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     0.9945     0.2741     0.25  
     3       3     0.4316     0.0942     0.25  
     4       4     0.7715     0.0908     0.25  
     5       5     0.2131     0.4506     0.25  
     6       6     0.2862     0.1644     0.0322
     7       2     0.0055     0.7259     0.75  
     8       3     0.5684     0.9058     0.75  
     9       4     0.2285     0.9092     0.75  
    10       5     0.7869     0.5494     0.75  
    11       6     0.7138     0.8356     0.9678
    12       1     0.0        0.0        0.5   
    13       6     0.7138     0.8356     0.5322
    14       6     0.2862     0.1644     0.4678
    15       1     0.5        0.5        0.0   
    16       2     0.5055     0.7741     0.25  
    17       3     0.0684     0.5942     0.25  
    18       4     0.7285     0.5908     0.25  
    19       5     0.2869     0.9506     0.25  
    20       6     0.2138     0.6644     0.0322
    21       2     0.4945     0.2259     0.75  
    22       3     0.9316     0.4058     0.75  
    23       4     0.2715     0.4092     0.75  
    24       5     0.7131     0.0494     0.75  
    25       6     0.7862     0.3356     0.9678
    26       1     0.5        0.5        0.5   
    27       6     0.7862     0.3356     0.5322
    28       6     0.2138     0.6644     0.4678


X-ray density (g/cm cub.)   =      3.48

MU (1/cm) =     106.736    Mass attenuation coefficient (cm**2/g) =     30.665

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

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

    1    Mg                  2.52         6
                                                 2.0166       4
                                                 2.108        6
                                                 2.0166       4
                                                 2.108        6
                                                 2.0394       5
                                                 2.0394       5
    2    Mg                  2.52         6
                                                 2.0844       4
                                                 2.0162       5
                                                 2.1536       6
                                                 2.1536       6
                                                 2.0062       6
                                                 2.0062       6
    3    Si                  2.1          4
                                                 1.587        4
                                                 1.5983       6
                                                 1.5983       6
                                                 1.5677       5
    4    O                   3.264       12
                                                 2.8132       6
                                                 2.6969       6
                                                 3.0177       6
                                                 3.0177       6
                                                 2.8132       6
                                                 2.6969       6
                                                 2.7742       5
                                                 2.6505       5
                                                 2.959        5
                                                 2.959        5
                                                 2.9212       6
                                                 2.9212       6
    5    O                   3.264       10
                                                 3.1117       6
                                                 3.1117       6
                                                 2.7742       4
                                                 2.6505       4
                                                 2.4602       6
                                                 2.959        4
                                                 2.959        4
                                                 2.8226       6
                                                 2.8226       6
                                                 2.4602       6
    6    O                   3.264       10
                                                 2.6969       4
                                                 2.8132       4
                                                 3.1117       5
                                                 3.0177       4
                                                 2.5422       6
                                                 2.4602       5
                                                 2.9212       4
                                                 2.8226       5
                                                 2.9041       6
                                                 2.9041       6

  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  8.996  17.993   0.102   78.86    2       28.6      179.5
    2   1   1   0 10.521  21.042   0.119   57.08    4       10.6       35.7
    3   0   2   1 11.808  23.615   0.133   44.88    4       49.1      601.5
    4   1   0   1 12.199  24.398   0.137   41.92    4       27.6      176.9
    5   1   1   1 13.021  26.042   0.146   36.54    8       17.4      123.4
    6   1   2   0 13.14   26.28    0.148   35.84    4       23.9      113.4
    7   1   2   1 15.241  30.481   0.171   26.14    8       12.6       46.0
    8   0   0   2 15.306  30.612   0.171   25.9     2       46.5      155.4
    9   1   3   0 16.666  33.331   0.186   21.55    4       66.1      523.0
   10   0   2   2 17.867  35.735   0.199   18.52    4        6.2        4.0
   11   0   4   0 18.224  36.449   0.203   17.73    2        3.6        0.6
   12   1   3   1 18.403  36.806   0.205   17.35    8       59.5      683.3
   13   1   1   2 18.722  37.444   0.208   16.71    8       66.9      831.2
   14   2   0   0 19.27   38.541   0.214   15.68    2       15.0        9.8
   15   2   1   0 19.826  39.651   0.22    14.72    4       34.6       98.0
   16   0   4   1 19.843  39.687   0.22    14.69    4       35.2      101.1
   17   1   2   2 20.388  40.776   0.226   13.83    8       48.3      357.7
   18   1   4   0 20.708  41.416   0.23    13.36    4       57.5      245.6
   19   2   1   1 21.342  42.684   0.236   12.49    8       38.0      200.7
   20   2   2   0 21.42   42.839   0.237   12.38    4        4.6        1.5
   21   1   4   1 22.175  44.35    0.245   11.46    8        2.8        1.0
   22   2   2   1 22.85   45.7     0.252   10.71    8        0.6        0.0
   23   1   3   2 22.941  45.882   0.253   10.61    8       21.8       56.2
   24   2   3   0 23.884  47.768   0.263    9.69    4       23.5       29.8
   25   0   4   2 24.158  48.316   0.266    9.44    4       18.3       17.6
   26   2   0   2 25.0    49.999   0.274    8.73    4       19.5       18.5
   27   1   5   0 25.108  50.216   0.275    8.64    4       34.8       58.1
   28   0   2   3 25.196  50.393   0.276    8.58    4       11.4        6.2
   29   2   3   1 25.205  50.41    0.276    8.57    8        3.5        1.2
   30   1   0   3 25.402  50.805   0.278    8.42    4        6.3        1.8
   31   2   1   2 25.454  50.907   0.279    8.38    8        5.0        2.3
   32   1   1   3 25.851  51.703   0.283    8.09    8       19.2       33.0
   33   1   4   2 26.185  52.37    0.286    7.86    8        6.2        3.4
   34   1   5   1 26.384  52.767   0.288    7.72    8       22.5       43.3
   35   2   2   2 26.783  53.566   0.292    7.46    8       82.3      560.9
   36   2   4   0 27.044  54.087   0.295    7.3     4       60.4      147.9
   37   1   2   3 27.167  54.334   0.296    7.22    8       21.3       36.4
   38   0   6   0 27.977  55.953   0.305    6.76    2        8.5        1.4
   39   2   4   1 28.258  56.516   0.307    6.61    8       38.8      110.2
   40   2   3   2 28.904  57.807   0.314    6.28    8       20.9       30.5
   41   0   6   1 29.165  58.33    0.316    6.15    4       55.9      106.9
   42   1   3   3 29.269  58.538   0.317    6.1     8       50.5      173.2
   43   1   6   0 29.821  59.641   0.323    5.85    4       17.2        9.6
   44   1   5   2 29.982  59.965   0.324    5.78    8       17.5       19.7
   45   3   1   0 30.078  60.155   0.325    5.74    4       29.8       28.4
   46   0   4   3 30.303  60.606   0.328    5.65    4       50.5       80.0
   47   2   5   0 30.771  61.542   0.332    5.46    4       11.1        3.8
   48   3   0   1 30.819  61.639   0.333    5.44    4       26.1       20.6
   49   1   6   1 30.964  61.929   0.334    5.38    8        3.8        0.9
   50   3   1   1 31.216  62.432   0.336    5.29    8       19.7       22.8
   51   3   2   0 31.275  62.55    0.337    5.26    4       28.7       24.1
   52   2   1   3 31.424  62.847   0.338    5.21    8       25.8       38.5
   53   2   4   2 31.718  63.437   0.341    5.1     8       27.1       41.8
   54   0   0   4 31.867  63.734   0.343    5.05    2      134.9      255.1
   55   2   5   1 31.894  63.789   0.343    5.04    8       27.7       43.0
   56   1   4   3 32.064  64.128   0.345    4.98    8       11.9        7.9
   57   3   2   1 32.389  64.778   0.348    4.88    8       13.0        9.1
   58   0   6   2 32.567  65.134   0.349    4.82    4      115.4      356.3
   59   2   2   3 32.593  65.185   0.35     4.81    8       18.5       18.3
   60   3   3   0 33.216  66.432   0.356    4.62    4       28.7       21.1
   61   0   2   4 33.41   66.819   0.357    4.56    4       20.3       10.4
   62   1   1   4 33.962  67.923   0.363    4.41    8        5.4        1.4
   63   1   6   2 34.264  68.528   0.365    4.33    8       11.2        6.0
   64   3   3   1 34.296  68.592   0.366    4.32    8       44.1       93.2
   65   2   3   3 34.494  68.988   0.368    4.27    8        5.6        1.5
   66   3   1   2 34.503  69.005   0.368    4.27    8       40.7       78.6
   67   1   7   0 34.864  69.728   0.371    4.18    4       60.5       84.8
   68   2   6   0 35.0    69.999   0.372    4.14    4       16.8        6.5
   69   1   2   4 35.087  70.173   0.373    4.12    8        8.2        3.1
   70   2   5   2 35.148  70.296   0.374    4.11    8       10.0        4.6
   71   1   5   3 35.477  70.954   0.377    4.03    8       14.3        9.1
   72   3   2   2 35.62   71.24    0.378    4.0     8       60.5      162.5
   73   3   4   0 35.842  71.684   0.38     3.95    4       53.5       62.9
   74   1   7   1 35.921  71.842   0.381    3.94    8       11.1        5.4
   75   2   6   1 36.055  72.11    0.382    3.91    8       13.5        7.9
   76   3   4   1 36.887  73.774   0.39     3.74    8       31.4       41.0
   77   1   3   4 36.928  73.856   0.39     3.73    8       42.8       75.8
   78   2   4   3 37.079  74.158   0.391    3.71    8       19.0       14.9
   79   3   3   2 37.451  74.902   0.395    3.64    8        7.8        2.5
   80   0   4   4 37.852  75.704   0.398    3.57    4        9.7        1.9
   81   0   6   3 37.871  75.742   0.398    3.57    4       45.2       40.5
   82   2   0   4 38.507  77.015   0.404    3.46    4       30.7       18.1
   83   0   8   0 38.718  77.435   0.406    3.43    2       12.3        1.4
   84   2   1   4 38.866  77.732   0.407    3.41    8       20.3       15.6
   85   1   7   2 39.023  78.047   0.409    3.39    8       15.6        9.2
   86   3   5   0 39.108  78.216   0.409    3.37    4       25.7       12.3
   87   2   6   2 39.153  78.307   0.41     3.37    8       22.9       19.6
   88   3   0   3 39.34   78.679   0.411    3.34    4       37.7       26.4
   89   1   4   4 39.452  78.903   0.412    3.33    8       24.1       21.5
   90   1   6   3 39.47   78.94    0.413    3.32    8       15.4        8.8
   91   3   1   3 39.696  79.393   0.415    3.29    8        7.3        1.9
   92   2   7   0 39.725  79.45    0.415    3.29    4       18.0        5.9
   93   0   8   1 39.736  79.473   0.415    3.29    4       21.2        8.2
   94   2   2   4 39.937  79.875   0.417    3.26    8        1.0        0.0
   95   3   4   2 39.964  79.927   0.417    3.26    8       21.1       16.2
   96   3   5   1 40.124  80.248   0.418    3.24    8        4.5        0.7
   97   1   8   0 40.307  80.614   0.42     3.22    4       11.5        2.4
   98   2   5   3 40.311  80.622   0.42     3.22    8       28.1       28.2
   99   2   7   1 40.737  81.474   0.424    3.17    8       14.1        7.0
  100   3   2   3 40.762  81.524   0.424    3.16    8        5.5        1.1
  101   4   0   0 41.304  82.608   0.428    3.11    2       70.5       42.9
  102   1   8   1 41.316  82.632   0.429    3.1     8        8.6        2.5
  103   4   1   0 41.657  83.313   0.431    3.07    4        3.9        0.3
  104   2   3   4 41.708  83.415   0.432    3.07    8       19.1       12.4
  105   3   3   3 42.526  85.051   0.439    2.99    8       38.1       48.3
  106   1   5   4 42.636  85.272   0.44     2.98    8       28.5       26.9
  107   4   1   1 42.66   85.32    0.44     2.98    8        8.2        2.2
  108   0   2   5 42.704  85.408   0.44     2.98    4       38.8       24.9
  109   4   2   0 42.713  85.425   0.44     2.98    4        1.6        0.0
  110   0   8   2 42.758  85.516   0.441    2.97    4       15.3        3.9
  111   1   0   5 42.864  85.727   0.442    2.96    4       28.0       12.9
  112   3   6   0 43.0    86.001   0.443    2.95    4        2.5        0.1
  113   3   5   2 43.141  86.281   0.444    2.94    8       30.1       29.7
  114   1   1   5 43.215  86.429   0.444    2.94    8        6.0        1.2
  115   4   2   1 43.713  87.425   0.449    2.9     8        3.6        0.4
  116   2   7   2 43.747  87.493   0.449    2.9     8       31.4       31.7
  117   3   6   1 44.0    88.0     0.451    2.88    8       33.4       35.7
  118   1   7   3 44.057  88.114   0.451    2.88    8       13.6        5.9
  119   2   4   4 44.167  88.333   0.452    2.87    8       36.6       42.7
  120   2   6   3 44.184  88.369   0.452    2.87    8       13.8        6.0
  121   1   2   5 44.267  88.533   0.453    2.87    8        1.0        0.0
  122   1   8   2 44.32   88.641   0.454    2.87    8       24.9       19.7
  123   4   3   0 44.466  88.932   0.455    2.86    4       24.8        9.8
  124   0   6   4 44.931  89.862   0.458    2.83    4       17.2        4.6
  125   3   4   3 44.98   89.961   0.459    2.83    8       34.4       37.2


  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   0   2   0   8.996  17.993  4.926        179.5     21.6     21.9     5.6
    2   1   1   0  10.521  21.042  4.21844       35.7      4.3      4.4     5.6
    3   0   2   1  11.808  23.615  3.7643       601.5     72.4     73.2     5.6
    4   1   0   1  12.199  24.398  3.64534      176.9     21.3     21.5     5.6
    5   1   1   1  13.021  26.042  3.41881      123.4     14.8     15.0     5.6
    6   1   2   0  13.14   26.28   3.38831      113.4     13.6     13.8     5.6
    7   1   2   1  15.241  30.481  2.93025       46.0      5.5      5.6     5.6
    8   0   0   2  15.306  30.612  2.918        155.4     18.7     18.8     5.6
    9   1   3   0  16.666  33.331  2.68592      523.0     62.9     63.2     5.7
   10   1   3   1  18.403  36.806  2.43991      683.3     82.2     82.2     5.7
   11   1   1   2  18.722  37.444  2.39981      831.2    100.0    100.0     5.7
   12   2   0   0  19.27   38.541  2.334          9.8      1.2      1.2     5.7
   13   0   4   1  19.843  39.687  2.26919      199.1     24.0     23.9     5.7
   14   1   2   2  20.388  40.776  2.21108      357.7     43.0     42.9     5.7
   15   1   4   0  20.708  41.416  2.17837      245.6     29.5     29.4     5.7
   16   2   1   1  21.342  42.684  2.11652      200.7     24.1     24.0     5.7
   17   1   3   2  22.941  45.882  1.97619       56.2      6.8      6.7     5.7
   18   2   3   0  23.884  47.768  1.90246       29.8      3.6      3.5     5.7
   19   0   4   2  24.158  48.316  1.88215       17.6      2.1      2.1     5.7
   20   2   0   2  25.0    49.999  1.82267       18.5      2.2      2.2     5.7
   21   1   5   0  25.108  50.216  1.8153        58.1      7.0      6.9     5.8
   22   1   1   3  25.851  51.703  1.76654       33.0      4.0      3.9     5.8
   23   1   5   1  26.384  52.767  1.73338       43.3      5.2      5.1     5.8
   24   2   2   2  26.783  53.566  1.70941      560.9     67.5     66.3     5.8
   25   2   4   0  27.044  54.087  1.69416      147.9     17.8     17.5     5.8
   26   1   2   3  27.167  54.334  1.68706       36.4      4.4      4.3     5.8
   27   2   4   1  28.258  56.516  1.62699      110.2     13.3     13.0     5.8
   28   2   3   2  28.904  57.807  1.59367       30.5      3.7      3.6     5.8
   29   0   6   1  29.165  58.33   1.58063      106.9     12.9     12.6     5.8
   30   1   3   3  29.269  58.538  1.57551      173.2     20.8     20.3     5.8
   31   1   6   0  29.821  59.641  1.54897        9.6      1.2      1.1     5.8
   32   1   5   2  29.982  59.965  1.54138       19.7      2.4      2.3     5.8
   33   3   1   0  30.078  60.155  1.53695       28.4      3.4      3.3     5.8
   34   0   4   3  30.303  60.606  1.5266        80.0      9.6      9.4     5.8
   35   3   0   1  30.819  61.639  1.50348       20.6      2.5      2.4     5.8
   36   3   1   1  31.216  62.432  1.48627       22.8      2.7      2.7     5.8
   37   3   2   0  31.275  62.55   1.48374       24.1      2.9      2.8     5.8
   38   2   1   3  31.424  62.847  1.47744       38.5      4.6      4.5     5.9
   39   2   4   2  31.718  63.437  1.46512       41.8      5.0      4.9     5.9
   40   0   0   4  31.867  63.734  1.459        298.1     35.9     34.7     5.9
   41   3   2   1  32.389  64.778  1.43799        9.1      1.1      1.1     5.9
   42   0   6   2  32.567  65.134  1.431        374.7     45.1     43.5     5.9
   43   3   3   0  33.216  66.432  1.40615       21.1      2.5      2.4     5.9
   44   0   2   4  33.41   66.819  1.39893       10.4      1.3      1.2     5.9
   45   3   3   1  34.296  68.592  1.36703       93.2     11.2     10.8     5.9
   46   3   1   2  34.503  69.005  1.35985       80.0      9.6      9.2     5.9
   47   1   7   0  34.864  69.728  1.34751       84.8     10.2      9.8     5.9
   48   1   5   3  35.477  70.954  1.3272         9.1      1.1      1.0     5.9
   49   3   2   2  35.62   71.24   1.32258      162.5     19.5     18.7     5.9
   50   3   4   0  35.842  71.684  1.31548       62.9      7.6      7.2     5.9
   51   3   4   1  36.887  73.774  1.28328       41.0      4.9      4.7     6.0
   52   1   3   4  36.928  73.856  1.28206       75.8      9.1      8.7     6.0
   53   2   4   3  37.079  74.158  1.27759       14.9      1.8      1.7     6.0
   54   0   6   3  37.871  75.742  1.25477       42.3      5.1      4.8     6.0
   55   2   0   4  38.507  77.015  1.23717       18.1      2.2      2.1     6.0
   56   2   1   4  38.866  77.732  1.22753       15.6      1.9      1.8     6.0
   57   1   7   2  39.023  78.047  1.22337        9.2      1.1      1.0     6.0
   58   3   5   0  39.108  78.216  1.22115       12.3      1.5      1.4     6.0
   59   2   6   2  39.153  78.307  1.21996       19.6      2.4      2.2     6.0
   60   3   0   3  39.34   78.679  1.21511       26.4      3.2      3.0     6.0
   61   1   4   4  39.452  78.903  1.21222       30.4      3.7      3.4     6.0
   62   0   8   1  39.736  79.473  1.20496       16.1      1.9      1.8     6.0
   63   3   4   2  39.964  79.927  1.19925       16.2      1.9      1.8     6.0
   64   2   5   3  40.311  80.622  1.19066       30.5      3.7      3.4     6.1
   65   4   0   0  41.304  82.608  1.167         45.5      5.5      5.1     6.1
   66   2   3   4  41.708  83.415  1.15774       12.4      1.5      1.4     6.1
   67   3   3   3  42.526  85.051  1.1396        48.3      5.8      5.4     6.1
   68   1   5   4  42.636  85.272  1.13722       29.1      3.5      3.2     6.1
   69   0   2   5  42.704  85.408  1.13575       24.9      3.0      2.8     6.1
   70   1   0   5  42.864  85.727  1.13234       12.9      1.6      1.4     6.1
   71   3   5   2  43.141  86.281  1.12649       29.7      3.6      3.3     6.1
   72   2   7   2  43.747  87.493  1.11397       31.7      3.8      3.5     6.2
   73   3   6   1  44.0    88.0    1.10886       35.7      4.3      3.9     6.2
   74   2   4   4  44.167  88.333  1.10554       48.7      5.9      5.4     6.2
   75   1   8   2  44.32   88.641  1.1025        19.7      2.4      2.2     6.2
   76   4   3   0  44.466  88.932  1.09963        9.8      1.2      1.1     6.2
   77   3   4   3  44.98   89.961  1.08971       37.2      4.5      4.1     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)