Institute of Experimental Mineralogy
Russian Academy of Sciences
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142432, Chernogolovka, Moscow district
A.V. Chichagov +7(496)52-22320
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MAGNESIOCHROMITE
6, t-spinel, syn, f-oxospinelides, sf-spinel, s-chromite
MgCrO(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 = 8.3329 alpha = 90.0
b = 8.3329 beta = 90.0
c = 8.3329 gamma = 90.0
Unit cell volume (cub. angs.) = 578.61
Molar volume ( cub.cm/mol.) = 43.57
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 = 1.00
2 0.5 0.5 0.5 0.0 Cr = 1.00
3 0.2612 0.2612 0.2612 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 0.2612 0.2612 0.2612
4 1 0.875 0.875 0.875
5 3 0.7388 0.7388 0.7388
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 0.2388 0.0112 0.5112
13 3 0.4888 0.9888 0.7612
14 3 0.5112 0.2388 0.0112
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 0.7612 0.4888 0.9888
19 3 0.0112 0.5112 0.2388
20 3 0.9888 0.7612 0.4888
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 0.2388 0.5112 0.0112
25 3 0.9888 0.4888 0.7612
26 3 0.0112 0.2388 0.5112
27 3 0.7612 0.9888 0.4888
28 3 0.5112 0.0112 0.2388
29 3 0.4888 0.7612 0.9888
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 0.4888 0.4888 0.2612
40 3 0.0112 0.7388 0.0112
41 3 0.7612 0.2612 0.7612
42 3 0.5112 0.7388 0.5112
43 3 0.7612 0.7612 0.2612
44 3 0.7388 0.0112 0.0112
45 3 0.2612 0.7612 0.7612
46 3 0.7388 0.5112 0.5112
47 3 0.9888 0.9888 0.2612
48 3 0.0112 0.0112 0.7388
49 3 0.4888 0.2612 0.4888
50 3 0.2388 0.7388 0.2388
51 3 0.9888 0.2612 0.9888
52 3 0.2388 0.2388 0.7388
53 3 0.2612 0.4888 0.4888
54 3 0.7388 0.2388 0.2388
55 3 0.2612 0.9888 0.9888
56 3 0.5112 0.5112 0.7388
X-ray density (g/cm cub.) = 4.41
MU (1/cm) = 968.693 Mass attenuation coefficient (cm**2/g) = 219.489
Selected interatomic distances (cation-anion,anion-anion):
NoP Atom Rad.sph. C.N. Distance NoP N.
(angs.) (angs.)
1 Mg 2.52 4
1.9652 3
1.9652 3
1.9652 3
1.9652 3
2 Cr 2.628 6
1.9946 3
1.9946 3
1.9946 3
1.9946 3
1.9946 3
1.9946 3
3 O 3.264 12
2.952 3
2.952 3
2.952 3
2.952 3
2.952 3
2.952 3
2.6831 3
3.2092 3
2.6831 3
3.2092 3
2.6831 3
3.2092 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 10.715 21.43 0.104 54.96 8 138.5 2519.4
2 2 2 0 17.674 35.349 0.17 18.96 12 77.2 404.7
3 3 1 0 19.843 39.686 0.19 14.69 24 0.0 0.0
4 1 1 3 20.855 41.711 0.199 13.15 24 189.3 3379.1
5 2 2 2 21.829 43.658 0.208 11.87 8 117.3 390.5
6 4 0 0 25.427 50.854 0.24 8.4 6 357.3 1922.1
7 3 3 1 27.897 55.795 0.262 6.8 24 59.5 172.9
8 2 2 4 31.726 63.452 0.294 5.1 24 57.8 122.0
9 1 1 5 33.901 67.802 0.312 4.43 24 188.1 1122.1
10 3 3 3 33.901 67.802 0.312 4.43 8 119.9 151.9
11 4 4 0 37.388 74.776 0.339 3.65 12 383.0 1918.5
12 5 3 0 38.748 77.496 0.35 3.43 24 0.0 0.0
13 5 3 1 39.423 78.845 0.355 3.33 48 79.7 303.2
14 4 4 2 40.094 80.188 0.36 3.24 24 8.2 1.6
15 6 2 0 42.756 85.513 0.379 2.97 24 45.7 44.6
16 3 3 5 44.739 89.478 0.393 2.84 24 132.6 358.1
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 10.715 21.43 4.811 2519.4 74.6 75.9 5.6
2 2 2 0 17.674 35.349 2.94613 404.7 12.0 12.0 5.7
3 1 1 3 20.855 41.711 2.51246 3379.1 100.0 100.0 5.7
4 2 2 2 21.829 43.658 2.4055 390.5 11.6 11.5 5.7
5 4 0 0 25.427 50.854 2.08323 1922.1 56.9 56.3 5.8
6 3 3 1 27.897 55.795 1.9117 172.9 5.1 5.0 5.8
7 2 2 4 31.726 63.452 1.70095 122.0 3.6 3.5 5.9
8 1 1 5 33.901 67.802 1.60367 1274.0 37.7 36.4 5.9
9 4 4 0 37.388 74.776 1.47306 1918.5 56.8 54.1 6.0
10 5 3 1 39.423 78.845 1.40852 303.2 9.0 8.5 6.0
11 6 2 0 42.756 85.513 1.31755 44.6 1.3 1.2 6.1
12 3 3 5 44.739 89.478 1.27076 358.1 10.6 9.8 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)
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