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

7, t-olivine, at 79 kbar, f-olivine, s-forsterite

Mg(2)SiO(4)


Orthorhombic  P bnm  Z = 4

R =0.033          NR =114

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 =   4.688    alpha =   90.0 
             b =   9.993    beta  =   90.0 
             c =   5.861    gamma =   90.0 

    Unit cell volume (cub. angs.) =   274.57

    Molar volume ( cub.cm/mol.) =    41.35

  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      0.38   Mg    = 1.00
   2 0.9929  0.2762  0.25     0.14   Mg    = 1.00
   3 0.4261  0.0945  0.25     0.01   Si    = 1.00
   4 0.767   0.0919  0.25     0.48   O     = 1.00
   5 0.2224  0.4479  0.25     0.44   O     = 1.00
   6 0.2777  0.1637  0.0336   0.12   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     0.9929     0.2762     0.25  
     3       3     0.4261     0.0945     0.25  
     4       4     0.767      0.0919     0.25  
     5       5     0.2224     0.4479     0.25  
     6       6     0.2777     0.1637     0.0336
     7       2     0.0071     0.7238     0.75  
     8       3     0.5739     0.9055     0.75  
     9       4     0.233      0.9081     0.75  
    10       5     0.7776     0.5521     0.75  
    11       6     0.7223     0.8363     0.9664
    12       1     0.0        0.0        0.5   
    13       6     0.7223     0.8363     0.5336
    14       6     0.2777     0.1637     0.4664
    15       1     0.5        0.5        0.0   
    16       2     0.5071     0.7762     0.25  
    17       3     0.0739     0.5945     0.25  
    18       4     0.733      0.5919     0.25  
    19       5     0.2776     0.9479     0.25  
    20       6     0.2223     0.6637     0.0336
    21       2     0.4929     0.2238     0.75  
    22       3     0.9261     0.4055     0.75  
    23       4     0.267      0.4081     0.75  
    24       5     0.7224     0.0521     0.75  
    25       6     0.7777     0.3363     0.9664
    26       1     0.5        0.5        0.5   
    27       6     0.7777     0.3363     0.5336
    28       6     0.2223     0.6637     0.4664


X-ray density (g/cm cub.)   =      3.4 

MU (1/cm) =     104.334    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
                                                 2.0454       4
                                                 2.0999       6
                                                 2.0454       4
                                                 2.0999       6
                                                 2.0277       5
                                                 2.0277       5
    2    Mg                  2.52         6
                                                 2.1245       4
                                                 2.0252       5
                                                 2.1576       6
                                                 2.1576       6
                                                 2.035        6
                                                 2.035        6
    3    Si                  2.1          4
                                                 1.5984       4
                                                 1.6034       6
                                                 1.6034       6
                                                 1.622        5
    4    O                   3.264       12
                                                 2.8028       6
                                                 2.7176       6
                                                 3.0546       6
                                                 3.0546       6
                                                 2.8028       6
                                                 2.7176       6
                                                 2.7929       5
                                                 2.7082       5
                                                 2.9647       5
                                                 2.9647       5
                                                 2.9547       6
                                                 2.9547       6
    5    O                   3.264       10
                                                 3.1211       6
                                                 3.1211       6
                                                 2.7929       4
                                                 2.7082       4
                                                 2.5018       6
                                                 2.9647       4
                                                 2.9647       4
                                                 2.8901       6
                                                 2.8901       6
                                                 2.5018       6
    6    O                   3.264       10
                                                 2.7176       4
                                                 2.8028       4
                                                 3.1211       5
                                                 3.0546       4
                                                 2.5366       6
                                                 2.5018       5
                                                 2.9547       4
                                                 2.8901       5
                                                 2.9367       6
                                                 2.9367       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  8.868  17.737   0.1     81.22    2       28.2      171.9
    2   1   1   0 10.457  20.913   0.118   57.81    4        8.2       20.4
    3   0   2   1 11.688  23.376   0.131   45.85    4       48.1      563.7
    4   1   0   1 12.146  24.292   0.137   42.3     4       29.5      195.1
    5   1   1   1 12.949  25.897   0.145   36.97    8       17.3      118.0
    6   1   2   0 13.021  26.042   0.146   36.54    4       25.4      125.2
    7   1   2   1 15.12   30.24    0.169   26.59    8       13.2       49.0
    8   0   0   2 15.239  30.478   0.171   26.14    2       46.2      148.3
    9   1   3   0 16.48   32.959   0.184   22.08    4       66.4      517.1
   10   0   2   2 17.742  35.483   0.198   18.8     4        7.7        5.9
   11   0   4   0 17.958  35.917   0.2     18.31    2        0.2        0.0
   12   1   3   1 18.218  36.437   0.203   17.74    8       60.2      681.3
   13   1   1   2 18.628  37.256   0.207   16.9     8       67.4      815.5
   14   2   0   0 19.185  38.37    0.213   15.83    2       10.4        4.5
   15   0   4   1 19.583  39.166   0.218   15.13    4       35.6      101.5
   16   2   1   0 19.727  39.454   0.219   14.88    4       32.8       84.9
   17   1   2   2 20.255  40.51    0.225   14.03    8       48.0      342.7
   18   1   4   0 20.449  40.898   0.227   13.74    4       57.4      240.4
   19   2   1   1 21.237  42.473   0.235   12.63    8       35.7      170.9
   20   2   2   0 21.283  42.567   0.236   12.56    4        5.0        1.6
   21   1   4   1 21.918  43.836   0.242   11.76    8        0.2        0.0
   22   2   2   1 22.708  45.417   0.251   10.86    8        3.0        1.1
   23   1   3   2 22.751  45.503   0.251   10.81    8       18.1       37.6
   24   2   3   0 23.692  47.385   0.261    9.86    4       24.9       32.5
   25   0   4   2 23.901  47.802   0.263    9.67    4       20.4       21.4
   26   1   5   0 24.77   49.539   0.272    8.92    4       34.8       57.2
   27   2   0   2 24.886  49.771   0.273    8.82    4       18.8       16.5
   28   2   3   1 25.01   50.02    0.274    8.72    8        4.4        1.8
   29   0   2   3 25.046  50.092   0.275    8.69    4        9.1        3.8
   30   1   0   3 25.286  50.573   0.277    8.51    4        6.4        1.8
   31   2   1   2 25.329  50.657   0.278    8.47    8        9.1        7.5
   32   1   1   3 25.724  51.448   0.282    8.18    8       18.2       28.8
   33   1   4   2 25.926  51.852   0.284    8.04    8        7.2        4.5
   34   1   5   1 26.047  52.093   0.285    7.95    8       20.2       34.3
   35   2   2   2 26.626  53.251   0.291    7.56    8       83.4      558.5
   36   2   4   0 26.783  53.567   0.293    7.46    4       63.7      160.7
   37   1   2   3 27.008  54.015   0.295    7.32    8       22.3       38.5
   38   0   6   0 27.548  55.096   0.3      7.0     2        6.7        0.8
   39   2   4   1 27.995  55.99    0.305    6.75    8       40.4      117.1
   40   2   3   2 28.696  57.392   0.312    6.38    8       22.2       33.3
   41   0   6   1 28.738  57.476   0.312    6.36    4       57.9      113.3
   42   1   3   3 29.06   58.119   0.315    6.2     8       51.0      170.9
   43   1   6   0 29.394  58.788   0.319    6.04    4       17.3        9.5
   44   1   5   2 29.643  59.287   0.321    5.93    8       19.9       24.8
   45   3   1   0 29.928  59.857   0.324    5.8     4       29.5       26.8
   46   0   4   3 30.034  60.069   0.325    5.76    4       51.9       82.2
   47   2   5   0 30.43   60.86    0.329    5.59    4        7.1        1.5
   48   1   6   1 30.538  61.075   0.33     5.55    8        1.5        0.1
   49   3   0   1 30.674  61.347   0.331    5.49    4       24.0       16.8
   50   3   1   1 31.06   62.12    0.335    5.34    8       22.4       28.5
   51   3   2   0 31.096  62.192   0.335    5.33    4       28.0       22.2
   52   2   1   3 31.267  62.533   0.337    5.27    8       25.0       35.0
   53   2   4   2 31.445  62.889   0.339    5.2     8       27.3       41.3
   54   2   5   1 31.551  63.103   0.34     5.16    8       29.5       47.8
   55   0   0   4 31.715  63.431   0.341    5.1     2      134.0      243.1
   56   1   4   3 31.789  63.579   0.342    5.08    8       10.7        6.2
   57   0   6   2 32.138  64.277   0.345    4.96    4      115.2      349.4
   58   3   2   1 32.204  64.407   0.346    4.94    8       13.5        9.5
   59   2   2   3 32.406  64.812   0.348    4.87    8       18.4       17.4
   60   3   3   0 32.989  65.977   0.353    4.69    4       31.1       24.1
   61   0   2   4 33.219  66.438   0.356    4.62    4       19.7        9.5
   62   1   1   4 33.79   67.579   0.361    4.46    8        4.1        0.8
   63   1   6   2 33.832  67.665   0.361    4.44    8        9.7        4.5
   64   3   3   1 34.063  68.127   0.364    4.38    8       37.9       66.8
   65   2   3   3 34.26   68.521   0.365    4.33    8        3.2        0.5
   66   3   1   2 34.327  68.655   0.366    4.31    8       38.3       67.2
   67   1   7   0 34.335  68.671   0.366    4.31    4       62.7       89.8
   68   2   6   0 34.566  69.132   0.368    4.25    4       14.3        4.6
   69   2   5   2 34.794  69.589   0.37     4.19    8        9.7        4.2
   70   1   2   4 34.886  69.772   0.371    4.17    8        9.5        4.0
   71   1   5   3 35.122  70.244   0.373    4.12    8       13.2        7.6
   72   1   7   1 35.39   70.781   0.376    4.05    8       12.6        6.8
   73   3   2   2 35.416  70.832   0.376    4.05    8       64.3      177.8
   74   3   4   0 35.55   71.1     0.377    4.02    4       56.0       66.9
   75   2   6   1 35.618  71.236   0.378    4.0     8       14.2        8.6
   76   3   4   1 36.59   73.18    0.387    3.8     8       31.9       40.9
   77   1   3   4 36.681  73.361   0.388    3.78    8       43.9       77.4
   78   2   4   3 36.781  73.562   0.389    3.76    8       19.0       14.3
   79   3   3   2 37.2    74.4     0.392    3.68    8        3.6        0.5
   80   0   6   3 37.426  74.853   0.394    3.64    4       46.1       41.0
   81   0   4   4 37.549  75.099   0.396    3.62    4        8.6        1.4
   82   0   8   0 38.072  76.145   0.4      3.53    2       11.6        1.3
   83   2   0   4 38.313  76.626   0.402    3.49    4       29.8       16.5
   84   1   7   2 38.483  76.965   0.404    3.47    8       15.6        9.0
   85   2   1   4 38.663  77.325   0.406    3.44    8       20.1       14.7
   86   2   6   2 38.703  77.406   0.406    3.43    8       18.9       13.0
   87   3   5   0 38.735  77.469   0.406    3.43    4       18.9        6.5
   88   1   6   3 39.018  78.036   0.409    3.39    8       18.8       12.7
   89   0   8   1 39.087  78.175   0.409    3.38    4       17.7        5.6
   90   1   4   4 39.139  78.278   0.41     3.37    8       22.7       18.5
   91   3   0   3 39.14   78.279   0.41     3.37    4       38.5       26.5
   92   2   7   0 39.181  78.361   0.41     3.36    4       19.2        6.6
   93   3   1   3 39.487  78.974   0.413    3.32    8       11.3        4.5
   94   3   4   2 39.648  79.296   0.414    3.3     8       19.7       13.6
   95   1   8   0 39.656  79.311   0.414    3.3     4       12.3        2.7
   96   2   2   4 39.705  79.411   0.415    3.29    8        1.3        0.1
   97   3   5   1 39.745  79.489   0.415    3.29    8        6.9        1.7
   98   2   5   3 39.931  79.861   0.417    3.26    8       29.0       29.1
   99   2   7   1 40.188  80.375   0.419    3.23    8       13.2        6.0
  100   3   2   3 40.524  81.048   0.422    3.19    8        5.0        0.8
  101   1   8   1 40.66   81.319   0.423    3.18    8        9.6        3.1
  102   4   0   0 41.089  82.179   0.427    3.13    2       72.3       43.4
  103   2   3   4 41.428  82.857   0.43     3.09    8       20.1       13.3
  104   4   1   0 41.433  82.865   0.43     3.09    4        7.2        0.8
  105   0   8   2 42.093  84.186   0.435    3.03    4       17.8        5.1
  106   1   5   4 42.24   84.479   0.436    3.02    8       28.2       25.5
  107   3   3   3 42.24   84.48    0.436    3.02    8       32.8       34.4
  108   4   1   1 42.428  84.856   0.438    3.0     8       10.7        3.7
  109   0   2   5 42.451  84.903   0.438    3.0     4       38.5       23.6
  110   4   2   0 42.46   84.92    0.438    3.0     4        0.3        0.0
  111   3   6   0 42.526  85.052   0.439    2.99    4        1.7        0.0
  112   1   0   5 42.637  85.274   0.44     2.98    4       30.1       14.3
  113   3   5   2 42.741  85.481   0.441    2.97    8       34.9       38.5
  114   1   1   5 42.979  85.957   0.443    2.96    8        6.7        1.4
  115   2   7   2 43.178  86.356   0.444    2.94    8       29.4       26.9
  116   4   2   1 43.452  86.904   0.446    2.92    8        8.0        2.0
  117   1   7   3 43.486  86.972   0.447    2.92    8       14.3        6.3
  118   3   6   1 43.518  87.036   0.447    2.92    8       32.9       33.4
  119   1   8   2 43.645  87.289   0.448    2.91    8       26.2       21.2
  120   2   6   3 43.701  87.402   0.448    2.9     8       15.3        7.2
  121   2   4   4 43.82   87.64    0.449    2.9     8       38.4       45.4
  122   1   2   5 44.001  88.003   0.451    2.88    8        1.0        0.0
  123   4   3   0 44.165  88.331   0.452    2.87    4       23.1        8.1
  124   2   8   0 44.327  88.654   0.454    2.86    4       43.3       28.5
  125   0   6   4 44.442  88.884   0.454    2.86    4       15.5        3.7
  126   3   4   3 44.627  89.255   0.456    2.85    8       36.2       39.5


  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   8.868  17.737  4.9965       171.9     21.1     21.4     5.6
    2   1   1   0  10.457  20.913  4.24417       20.4      2.5      2.5     5.6
    3   0   2   1  11.688  23.376  3.80234      563.7     69.1     69.9     5.6
    4   1   0   1  12.146  24.292  3.66096      195.1     23.9     24.2     5.6
    5   1   1   1  12.949  25.897  3.43754      118.0     14.5     14.6     5.6
    6   1   2   0  13.021  26.042  3.41878      125.2     15.4     15.5     5.6
    7   1   2   1  15.12   30.24   2.9531        49.0      6.0      6.1     5.6
    8   0   0   2  15.239  30.478  2.9305       148.3     18.2     18.3     5.6
    9   1   3   0  16.48   32.959  2.71535      517.1     63.4     63.7     5.6
   10   1   3   1  18.218  36.437  2.46378      681.3     83.5     83.6     5.7
   11   1   1   2  18.628  37.256  2.4115       815.5    100.0    100.0     5.7
   12   0   4   1  19.583  39.166  2.29818      101.5     12.4     12.4     5.7
   13   2   1   0  19.727  39.454  2.28206       84.9     10.4     10.4     5.7
   14   1   2   2  20.255  40.51   2.22496      342.7     42.0     41.9     5.7
   15   1   4   0  20.449  40.898  2.20473      240.4     29.5     29.4     5.7
   16   2   1   1  21.237  42.473  2.12655      170.9     21.0     20.8     5.7
   17   1   3   2  22.751  45.503  1.99177       37.6      4.6      4.6     5.7
   18   2   3   0  23.692  47.385  1.91695       32.5      4.0      3.9     5.7
   19   0   4   2  23.901  47.802  1.90117       21.4      2.6      2.6     5.7
   20   1   5   0  24.77   49.539  1.8385        57.2      7.0      6.9     5.7
   21   2   0   2  24.886  49.771  1.83048       16.5      2.0      2.0     5.7
   22   1   1   3  25.724  51.448  1.77467       28.8      3.5      3.5     5.8
   23   1   5   1  26.047  52.093  1.75422       34.3      4.2      4.1     5.8
   24   2   2   2  26.626  53.251  1.71877      558.5     68.5     67.3     5.8
   25   2   4   0  26.783  53.567  1.70939      160.7     19.7     19.4     5.8
   26   1   2   3  27.008  54.015  1.69624       38.5      4.7      4.6     5.8
   27   2   4   1  27.995  55.99   1.64102      117.1     14.4     14.1     5.8
   28   2   3   2  28.696  57.392  1.60421       33.3      4.1      4.0     5.8
   29   0   6   1  28.738  57.476  1.60207      113.3     13.9     13.6     5.8
   30   1   3   3  29.06   58.119  1.58585      170.9     21.0     20.5     5.8
   31   1   6   0  29.394  58.788  1.5694         9.5      1.2      1.1     5.8
   32   1   5   2  29.643  59.287  1.55738       24.8      3.0      3.0     5.8
   33   3   1   0  29.928  59.857  1.5439        26.8      3.3      3.2     5.8
   34   0   4   3  30.034  60.069  1.53897       82.2     10.1      9.8     5.8
   35   3   0   1  30.674  61.347  1.50992       16.8      2.1      2.0     5.8
   36   3   1   1  31.06   62.12   1.49297       28.5      3.5      3.4     5.8
   37   3   2   0  31.096  62.192  1.49143       22.2      2.7      2.6     5.8
   38   2   1   3  31.267  62.533  1.4841        35.0      4.3      4.2     5.8
   39   2   4   2  31.445  62.889  1.47655       41.3      5.1      4.9     5.9
   40   2   5   1  31.551  63.103  1.47207       47.8      5.9      5.7     5.9
   41   0   0   4  31.715  63.431  1.46525      243.1     29.8     28.9     5.9
   42   0   6   2  32.138  64.277  1.44799      349.4     42.8     41.4     5.9
   43   3   2   1  32.204  64.407  1.44536        9.5      1.2      1.1     5.9
   44   2   2   3  32.406  64.812  1.43731       17.4      2.1      2.1     5.9
   45   3   3   0  32.989  65.977  1.41472       24.1      3.0      2.8     5.9
   46   0   2   4  33.219  66.438  1.40604        9.5      1.2      1.1     5.9
   47   3   3   1  34.063  68.127  1.37523       66.8      8.2      7.9     5.9
   48   1   7   0  34.335  68.671  1.36566      157.0     19.3     18.5     5.9
   49   3   2   2  35.416  70.832  1.32919      184.6     22.6     21.6     5.9
   50   3   4   0  35.55   71.1    1.32484       66.9      8.2      7.8     5.9
   51   2   6   1  35.618  71.236  1.32265        8.6      1.1      1.0     5.9
   52   3   4   1  36.59   73.18   1.29224       40.9      5.0      4.8     6.0
   53   1   3   4  36.681  73.361  1.28949       77.4      9.5      9.0     6.0
   54   2   4   3  36.781  73.562  1.28647       14.3      1.8      1.7     6.0
   55   0   6   3  37.426  74.853  1.26745       41.0      5.0      4.8     6.0
   56   2   0   4  38.313  76.626  1.24247       16.5      2.0      1.9     6.0
   57   1   7   2  38.483  76.965  1.23784        9.0      1.1      1.0     6.0
   58   2   1   4  38.663  77.325  1.23298       14.7      1.8      1.7     6.0
   59   2   6   2  38.703  77.406  1.23189       13.0      1.6      1.5     6.0
   60   1   6   3  39.018  78.036  1.22352       12.7      1.6      1.5     6.0
   61   3   0   3  39.14   78.279  1.22032       45.0      5.5      5.2     6.0
   62   3   4   2  39.648  79.296  1.2072        16.3      2.0      1.9     6.0
   63   2   5   3  39.931  79.861  1.20008       29.1      3.6      3.3     6.0
   64   4   0   0  41.089  82.179  1.172         43.4      5.3      5.0     6.1
   65   2   3   4  41.428  82.857  1.16412       14.1      1.7      1.6     6.1
   66   3   3   3  42.24   84.48   1.14585       59.9      7.3      6.8     6.1
   67   0   2   5  42.451  84.903  1.14121       27.2      3.3      3.1     6.1
   68   1   0   5  42.637  85.274  1.13719       14.3      1.8      1.6     6.1
   69   3   5   2  42.741  85.481  1.13497       38.5      4.7      4.4     6.1
   70   2   7   2  43.178  86.356  1.1257        26.9      3.3      3.1     6.1
   71   3   6   1  43.518  87.036  1.11864       33.4      4.1      3.8     6.1
   72   1   8   2  43.645  87.289  1.11605       21.2      2.6      2.4     6.2
   73   2   4   4  43.82   87.64   1.11248       45.4      5.6      5.1     6.2
   74   2   8   0  44.327  88.654  1.10237       28.5      3.5      3.2     6.2
   75   3   4   3  44.627  89.255  1.0965        39.5      4.8      4.4     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)