Institute of Experimental Mineralogy
                 Russian Academy of Sciences
     -------------------------------------------------
           142432, Chernogolovka, Moscow district
             A.V. Chichagov  +7(496)52-22320

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          ***      W W W - X R A Y P O L       ***
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MAGNESIOCHROMITE

3, t-spinel, syn, f-oxospinelides, sf-spinel, s-chromite

Mg(0.80)Fe(0.20)Cr(2)O(4)


Cubic  * Fd3m  Z = 8

*Fd3m

21 .8 .9

Ref.Str.:

         Lenaz D., Skogby H., Princivalle F., Halenius U. (2004)

         * Phys. Chem. Minerals, 31, 633-642

         R: N.A.D.

                   Initial data from BDM-file 

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

             a =   8.3415   alpha =   90.0 
             b =   8.3415   beta  =   90.0 
             c =   8.3415   gamma =   90.0 

    Unit cell volume (cub. angs.) =   580.41

    Molar volume ( cub.cm/mol.) =    43.7 

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

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

   1 0.125   0.125   0.125    0.0    Mg    = 0.63, Fe    = 0.37
   2 0.5     0.5     0.5      0.0    Cr    = 1.00
   3 0.2615  0.2615  0.2615   0.0    O     = 1.00


  Co-ordinates for all atomic positions :

   No       NoP      x/a        y/b       z/c 

     1       1     0.125      0.125      0.125 
     2       2     0.5        0.5        0.5   
     3       3     0.2615     0.2615     0.2615
     4       1     0.875      0.875      0.875 
     5       3     0.7385     0.7385     0.7385
     6       1     0.375      0.875      0.375 
     7       1     0.625      0.125      0.625 
     8       1     0.375      0.375      0.875 
     9       2     0.0        0.25       0.75  
    10       2     0.25       0.75       0.0   
    11       2     0.75       0.0        0.25  
    12       3     0.2385     0.0115     0.5115
    13       3     0.4885     0.9885     0.7615
    14       3     0.5115     0.2385     0.0115
    15       1     0.625      0.625      0.125 
    16       1     0.875      0.375      0.375 
    17       1     0.125      0.625      0.625 
    18       3     0.7615     0.4885     0.9885
    19       3     0.0115     0.5115     0.2385
    20       3     0.9885     0.7615     0.4885
    21       2     0.0        0.75       0.25  
    22       2     0.75       0.25       0.0   
    23       2     0.25       0.0        0.75  
    24       3     0.2385     0.5115     0.0115
    25       3     0.9885     0.4885     0.7615
    26       3     0.0115     0.2385     0.5115
    27       3     0.7615     0.9885     0.4885
    28       3     0.5115     0.0115     0.2385
    29       3     0.4885     0.7615     0.9885
    30       2     0.25       0.25       0.5   
    31       2     0.25       0.5        0.25  
    32       2     0.0        0.5        0.0   
    33       2     0.75       0.5        0.75  
    34       2     0.0        0.0        0.5   
    35       2     0.5        0.25       0.25  
    36       2     0.5        0.0        0.0   
    37       2     0.5        0.75       0.75  
    38       2     0.75       0.75       0.5   
    39       3     0.4885     0.4885     0.2615
    40       3     0.0115     0.7385     0.0115
    41       3     0.7615     0.2615     0.7615
    42       3     0.5115     0.7385     0.5115
    43       3     0.7615     0.7615     0.2615
    44       3     0.7385     0.0115     0.0115
    45       3     0.2615     0.7615     0.7615
    46       3     0.7385     0.5115     0.5115
    47       3     0.9885     0.9885     0.2615
    48       3     0.0115     0.0115     0.7385
    49       3     0.4885     0.2615     0.4885
    50       3     0.2385     0.7385     0.2385
    51       3     0.9885     0.2615     0.9885
    52       3     0.2385     0.2385     0.7385
    53       3     0.2615     0.4885     0.4885
    54       3     0.7385     0.2385     0.2385
    55       3     0.2615     0.9885     0.9885
    56       3     0.5115     0.5115     0.7385


X-ray density (g/cm cub.)   =      4.67

MU (1/cm) =     978.42     Mass attenuation coefficient (cm**2/g) =    209.656

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

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

    1   Mg   ,Fe             2.592        4
                                                 1.9721       3
                                                 1.9721       3
                                                 1.9721       3
                                                 1.9721       3
    2    Cr                  2.628        6
                                                 1.9941       3
                                                 1.9941       3
                                                 1.9941       3
                                                 1.9941       3
                                                 1.9941       3
                                                 1.9941       3
    3    O                   3.264       12
                                                 2.9554       3
                                                 2.9554       3
                                                 2.9554       3
                                                 2.9554       3
                                                 2.9554       3
                                                 2.9554       3
                                                 2.6778       3
                                                 3.2205       3
                                                 2.6778       3
                                                 3.2205       3
                                                 2.6778       3
                                                 3.2205       3

  X-ray diffraction powder data (II),  X-Ray W.L. =   1.78892(angs.):

  No   H   K   L   Theta 2*Theta    S       LPG   MF        F          I int.
                    ( degree )                                         *100

    1   1   1   1 10.704  21.407   0.104   55.08    8      111.8     1633.4
    2   2   2   0 17.655  35.311   0.17    19.01   12      112.8      861.0
    3   3   1   0 19.822  39.643   0.19    14.73   24        0.0        0.0
    4   1   1   3 20.833  41.666   0.199   13.18   24      212.9     4257.7
    5   2   2   2 21.805  43.611   0.208   11.9     8      117.7      391.1
    6   4   0   0 25.399  50.798   0.24     8.42    6      326.1     1595.3
    7   3   3   1 27.866  55.732   0.261    6.82   24       37.8       69.6
    8   2   2   4 31.69   63.379   0.294    5.11   24       85.5      266.3
    9   1   1   5 33.861  67.723   0.311    4.44   24      208.1     1368.1
   10   3   3   3 33.861  67.723   0.311    4.44    8      137.8      200.2
   11   4   4   0 37.343  74.686   0.339    3.66   12      408.2     2170.7
   12   5   3   0 38.701  77.402   0.35     3.43   24        0.0        0.0
   13   5   3   1 39.374  78.748   0.355    3.34   48       62.6      186.3
   14   4   4   2 40.044  80.089   0.36     3.25   24        8.7        1.8
   15   6   2   0 42.702  85.404   0.379    2.98   24       69.0      100.9
   16   3   3   5 44.681  89.361   0.393    2.84   24      148.9      449.5


  X-ray diffraction powder data (I)...X-Ray wave length =  1.78892 (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   1   1   1  10.704  21.407  4.81597     1633.4     38.4     39.0     5.6
    2   2   2   0  17.655  35.311  2.94917      861.0     20.2     20.3     5.7
    3   1   1   3  20.833  41.666  2.51506     4257.7    100.0    100.0     5.7
    4   2   2   2  21.805  43.611  2.40798      391.1      9.2      9.2     5.7
    5   4   0   0  25.399  50.798  2.08538     1595.3     37.5     37.1     5.8
    6   3   3   1  27.866  55.732  1.91367       69.6      1.6      1.6     5.8
    7   2   2   4  31.69   63.379  1.7027       266.3      6.3      6.1     5.9
    8   1   1   5  33.861  67.723  1.60532     1568.3     36.8     35.6     5.9
    9   4   4   0  37.343  74.686  1.47458     2170.7     51.0     48.6     6.0
   10   5   3   1  39.374  78.748  1.40997      186.3      4.4      4.1     6.0
   11   6   2   0  42.702  85.404  1.31891      100.9      2.4      2.2     6.1
   12   3   3   5  44.681  89.361  1.27207      449.5     10.6      9.7     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)