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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SPINEL

49, t-spinel, analogue

MgGa(2)O(4)


Cubic  * Fd3m  Z = 8

R =0.0596

4 .3 .1902

Ref.Str.:

         R.L. Millard, R.C. Peterson, I.P. Swainson (2000)

         * Phys. Chem. Minerals, 27, 179-193

Reserv:

         N.A.D.

                   Initial data from BDM-file 

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

             a =   8.2891   alpha =   90.0 
             b =   8.2891   beta  =   90.0 
             c =   8.2891   gamma =   90.0 

    Unit cell volume (cub. angs.) =   569.54

    Molar volume ( cub.cm/mol.) =    42.88

  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    0.41   Mg    = 1.00
   2 0.5     0.5     0.5      0.27   Ga    = 1.00
   3 0.2567  0.2567  0.2567   0.5    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     0.2567     0.2567     0.2567
     4       1     0.875      0.875      0.875 
     5       3     0.7433     0.7433     0.7433
     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     0.2433     0.0067     0.5067
    13       3     0.4933     0.9933     0.7567
    14       3     0.5067     0.2433     0.0067
    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     0.7567     0.4933     0.9933
    19       3     0.0067     0.5067     0.2433
    20       3     0.9933     0.7567     0.4933
    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     0.2433     0.5067     0.0067
    25       3     0.9933     0.4933     0.7567
    26       3     0.0067     0.2433     0.5067
    27       3     0.7567     0.9933     0.4933
    28       3     0.5067     0.0067     0.2433
    29       3     0.4933     0.7567     0.9933
    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     0.4933     0.4933     0.2567
    40       3     0.0067     0.7433     0.0067
    41       3     0.7567     0.2567     0.7567
    42       3     0.5067     0.7433     0.5067
    43       3     0.7567     0.7567     0.2567
    44       3     0.7433     0.0067     0.0067
    45       3     0.2567     0.7567     0.7567
    46       3     0.7433     0.5067     0.5067
    47       3     0.9933     0.9933     0.2567
    48       3     0.0067     0.0067     0.7433
    49       3     0.4933     0.2567     0.4933
    50       3     0.2433     0.7433     0.2433
    51       3     0.9933     0.2567     0.9933
    52       3     0.2433     0.2433     0.7433
    53       3     0.2567     0.4933     0.4933
    54       3     0.7433     0.2433     0.2433
    55       3     0.2567     0.9933     0.9933
    56       3     0.5067     0.5067     0.7433


X-ray density (g/cm cub.)   =      5.31

MU (1/cm) =     259.802    Mass attenuation coefficient (cm**2/g) =     48.924

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

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

    1    Mg                  2.52         4
                                                 1.8908       3
                                                 1.8908       3
                                                 1.8908       3
                                                 1.8908       3
    2    Ga                  2.376        6
                                                 2.0183       3
                                                 2.0183       3
                                                 2.0183       3
                                                 2.0183       3
                                                 2.0183       3
                                                 2.0183       3
    3    O                   3.264       12
                                                 2.9327       3
                                                 2.9327       3
                                                 2.9327       3
                                                 2.9327       3
                                                 2.9327       3
                                                 2.9327       3
                                                 2.7736       3
                                                 3.0877       3
                                                 2.7736       3
                                                 3.0877       3
                                                 2.7736       3
                                                 3.0877       3

  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  9.262  18.525   0.104   74.27    8      171.9     5413.6
    2   2   2   0 15.238  30.477   0.171   26.15   12       75.1      545.6
    3   3   1   0 17.089  34.178   0.191   20.41   24        0.0        0.0
    4   1   1   3 17.951  35.902   0.2     18.33   24      232.4     7321.2
    5   2   2   2 18.778  37.557   0.209   16.6     8      196.8     1585.6
    6   4   0   0 21.821  43.642   0.241   11.88    6      436.4     4185.2
    7   3   3   1 23.895  47.79    0.263    9.68   24      108.6      844.4
    8   2   2   4 27.081  54.162   0.296    7.28   24       58.5      184.0
    9   1   1   5 28.872  57.745   0.313    6.29   24      211.8     2087.9
   10   3   3   3 28.872  57.745   0.313    6.29    8      171.6      456.9
   11   4   4   0 31.714  63.427   0.341    5.11   12      452.5     3867.5
   12   5   3   0 32.81   65.62    0.352    4.74   24        0.0        0.0
   13   5   3   1 33.351  66.701   0.357    4.58   48      110.8      832.0
   14   4   4   2 33.887  67.775   0.362    4.43   24        2.9        0.3
   15   6   2   0 35.995  71.991   0.381    3.92   24       47.7       66.1
   16   3   3   5 37.543  75.087   0.396    3.62   24      163.4      715.6
   17   2   2   6 38.054  76.108   0.4      3.54   24      172.7      779.8
   18   4   4   4 40.077  80.154   0.418    3.25    8      286.2      655.7
   19   7   1   0 41.078  82.157   0.427    3.13   24        0.0        0.0
   20   1   1   7 41.577  83.155   0.431    3.08   24       81.8      152.3
   21   5   5   1 41.577  83.155   0.431    3.08   24      108.9      270.0
   22   6   4   2 44.059  88.118   0.451    2.88   48       43.9       82.3


  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   1   1   1   9.262  18.525  4.78571     5413.6     73.9     75.0     5.6
    2   2   2   0  15.238  30.477  2.93064      545.6      7.5      7.5     5.6
    3   1   1   3  17.951  35.902  2.49926     7321.2    100.0    100.0     5.7
    4   2   2   2  18.778  37.557  2.39286     1585.6     21.7     21.6     5.7
    5   4   0   0  21.821  43.642  2.07228     4185.2     57.2     56.7     5.7
    6   3   3   1  23.895  47.79   1.90165      844.4     11.5     11.4     5.7
    7   2   2   4  27.081  54.162  1.69201      184.0      2.5      2.5     5.8
    8   1   1   5  28.872  57.745  1.59524     2544.8     34.8     33.9     5.8
    9   4   4   0  31.714  63.427  1.46532     3867.5     52.8     51.1     5.9
   10   5   3   1  33.351  66.701  1.40111      832.0     11.4     10.9     5.9
   11   3   3   5  37.543  75.087  1.26408      715.6      9.8      9.3     6.0
   12   2   2   6  38.054  76.108  1.24963      779.8     10.7     10.1     6.0
   13   4   4   4  40.077  80.154  1.19643      655.7      9.0      8.4     6.0
   14   5   5   1  41.577  83.155  1.16071      422.3      5.8      5.4     6.1
   15   6   4   2  44.059  88.118  1.10768       82.3      1.1      1.0     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)