-    SILLIMANITE     -    Al2SiO5

Theoretical atomic positions and lattice parameters from AMCSD 

Crystal Structure 


Because of the translational symmetry all the calculations are performed in the primitive unit cell and not in the conventional unit cell. The following information regarding the structure is given with respect to this primitive unit cell, which sometimes can take an unintuitive shape.

Symmetry (experimental): 

Space group:  62  Pnma 
Lattice parameters (Å):  7.4857  7.6750  5.7751 
Angles (°):  90.0  90.0  90.0 

Symmetry (theoretical): 

Space group:  62  Pnma 
Lattice parameters (Å):  7.4857  7.6750  5.7751 
Angles (°):  90.0  90.0  90.0 

Cell contents: 

Number of atoms:  32 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Al:  0.0000  0.0000  0.0000 
Al:  0.1417  0.3452  0.2500 
Si:  0.1532  0.3404  0.7500 
O:  0.3602  0.4089  0.7500 
O:  0.3566  0.4339  0.2500 
O:  0.4767  0.0009  0.7500 
O:  0.1255  0.2232  0.5145 
Al:  0.5000  0.5000  0.0000 
Al:  0.6417  0.1548  0.7500 
Si:  0.6532  0.1596  0.2500 
O:  0.8602  0.0911  0.2500 
O:  0.8566  0.0661  0.7500 
O:  0.9767  0.4991  0.2500 
O:  0.6255  0.2768  0.4855 
Al:  0.0000  0.0000  0.5000 
Al:  0.8583  0.6548  0.7500 
Si:  0.8468  0.6596  0.2500 
O:  0.6398  0.5911  0.2500 
O:  0.6434  0.5661  0.7500 
O:  0.5233  0.9991  0.2500 
O:  0.8745  0.7768  0.0145 
Al:  0.5000  0.5000  0.5000 
Al:  0.3583  0.8452  0.2500 
Si:  0.3468  0.8404  0.7500 
O:  0.1398  0.9089  0.7500 
O:  0.1434  0.9339  0.2500 
O:  0.0233  0.5009  0.7500 
O:  0.3745  0.7232  0.9855 
O:  0.8745  0.7768  0.4855 
O:  0.3745  0.7232  0.5145 
O:  0.1255  0.2232  0.9855 
O:  0.6255  0.2768  0.0145 
Atom type 

We have listed here the reduced coordinates of all the atoms in the primitive unit cell.
It is enough to know only the position of the atoms from the assymetrical unit cell and then use the symmetry to build the whole crystal structure.

Visualization of the crystal structure: 

Size:

  
Nx:  Ny:  Nz:    
You can define the size of the supercell to be displayed in the jmol panel as integer translations along the three crys­tallo­gra­phic axis.
Please note that the structure is represented using the pri­mi­tive cell, and not the conventional one.
     

Powder Raman 

Powder Raman spectrum

The intensity of the Raman peaks is computed within the density-functional perturbation theory. The intensity depends on the temperature (for now fixed at 300K), frequency of the input laser (for now fixed at 21834 cm-1, frequency of the phonon mode and the Raman tensor. The Raman tensor represents the derivative of the dielectric tensor during the atomic displacement that corresponds to the phonon vibration. The Raman tensor is related to the polarizability of a specific phonon mode.

Horizontal:
Xmin:
Xmax:
Vertical:
Ymin:
Ymax:
 
Choose the polarization of the lasers.
I ∥ 
I ⊥ 
I Total 

Data about the phonon modes

Frequency of the transverse (TO) and longitudinal (LO) phonon modes in the zone-center. The longitudinal modes are computed along the three cartesian directions. You can visualize the atomic displacement pattern corresponding to each phonon by clicking on the appropriate cell in the table below.

1
ac
0
0
0
0
2
ac
0
0
0
0
3
ac
0
0
0
0
4
B3u
121
122
121
121
5
A1g
146
146
146
146
2.056e+39
12.0
1.038e+38
0.6
2.160e+39
12.6
6
B2u
147
147
147
147
7
Au
147
147
147
147
8
B1g
171
171
171
171
2.661e+36
0.0
3.659e+36
0.0
6.320e+36
0.0
9
B1g
189
189
189
189
10
B2u
193
193
194
193
11
B1u
199
199
199
202
12
B2g
202
202
202
211
1.940e+38
1.1
2.668e+38
1.6
4.608e+38
2.7
13
B3g
211
211
211
216
1.079e+38
0.6
1.484e+38
0.9
2.564e+38
1.5
14
Au
234
234
234
234
15
A1g
236
236
236
236
5.971e+39
34.9
2.260e+38
1.3
6.197e+39
36.3
16
Au
248
248
248
248
17
B2g
254
254
254
254
2.095e+37
0.1
2.881e+37
0.2
4.976e+37
0.3
18
B1g
258
258
258
258
19
B3u
258
260
258
258
20
B3g
260
265
260
260
2.644e+36
0.0
3.635e+36
0.0
6.279e+36
0.0
21
B1u
274
274
274
274
22
B3u
282
284
282
282
23
B1u
284
284
284
284
24
A1g
291
291
291
291
5.566e+38
3.3
1.066e+38
0.6
6.631e+38
3.9
25
Au
294
294
294
294
26
A1g
301
301
301
301
1.608e+40
94.1
1.014e+39
5.9
1.709e+40
100.0
27
B1u
305
305
305
306
28
B1g
306
306
306
306
1.146e+38
0.7
1.576e+38
0.9
2.723e+38
1.6
29
Au
307
307
307
307
30
B2u
319
319
326
319
31
B3u
326
326
326
326
32
B2u
328
328
329
328
33
B2g
330
330
330
330
8.669e+37
0.5
1.192e+38
0.7
2.059e+38
1.2
34
B3u
336
337
336
336
35
B1u
350
350
350
355
36
A1g
357
357
357
357
1.651e+38
1.0
5.993e+37
0.4
2.250e+38
1.3
37
Au
364
364
364
364
38
B3g
372
372
372
372
1.097e+38
0.6
1.508e+38
0.9
2.605e+38
1.5
39
B1g
375
375
375
375
6.828e+38
4.0
9.388e+38
5.5
1.622e+39
9.5
40
B2u
380
380
380
380
41
A1g
396
396
396
396
6.515e+38
3.8
6.560e+37
0.4
7.171e+38
4.2
42
B1g
401
401
401
401
1.587e+39
9.3
2.182e+39
12.8
3.768e+39
22.0
43
B3g
405
405
405
405
3.711e+36
0.0
5.103e+36
0.0
8.814e+36
0.1
44
B2u
405
405
411
405
45
B2g
411
411
413
411
2.981e+38
1.7
4.099e+38
2.4
7.080e+38
4.1
46
B3u
413
424
414
413
47
B2u
424
436
436
424
48
Au
436
439
439
436
49
B1g
439
441
441
439
50
A1g
441
452
452
441
7.270e+39
42.5
1.152e+39
6.7
8.422e+39
49.3
51
B1u
452
457
457
457
52
B2g
457
458
471
464
5.033e+38
2.9
6.920e+38
4.0
1.195e+39
7.0
53
B3u
471
494
490
471
54
B2u
494
496
496
494
55
B3g
496
503
503
496
1.046e+38
0.6
1.438e+38
0.8
2.484e+38
1.5
56
Au
503
504
510
503
57
B1u
510
510
522
522
58
B3u
522
535
536
562
59
A1g
562
562
562
564
4.804e+39
28.1
1.455e+38
0.9
4.950e+39
29.0
60
B3g
564
564
564
569
7.226e+37
0.4
9.935e+37
0.6
1.716e+38
1.0
61
B2u
569
569
571
577
62
B3u
577
577
577
577
63
B3u
586
586
586
586
64
B2u
587
587
592
587
65
B1u
592
592
593
593
66
Au
593
593
610
606
67
B2g
610
610
617
610
2.391e+36
0.0
3.287e+36
0.0
5.678e+36
0.0
68
B1g
617
617
622
617
5.395e+37
0.3
7.419e+37
0.4
1.281e+38
0.7
69
B2g
634
634
634
634
5.952e+35
0.0
8.183e+35
0.0
1.413e+36
0.0
70
Au
634
634
634
634
71
B1u
638
638
638
655
72
B3g
655
655
655
662
1.344e+39
7.9
1.848e+39
10.8
3.192e+39
18.7
73
A1g
662
662
662
669
1.732e+39
10.1
9.339e+38
5.5
2.666e+39
15.6
74
B3u
669
669
669
689
75
B2u
689
689
714
700
76
B1g
715
715
715
715
5.232e+37
0.3
7.194e+37
0.4
1.243e+38
0.7
77
B1g
725
725
725
725
1.658e+37
0.1
2.279e+37
0.1
3.937e+37
0.2
78
A1g
728
728
728
728
7.125e+37
0.4
5.343e+37
0.3
1.247e+38
0.7
79
B3u
746
750
746
746
80
B2u
750
806
774
750
81
A1g
825
825
825
825
5.994e+39
35.1
1.132e+39
6.6
7.126e+39
41.7
82
B3u
838
852
838
838
83
B2u
852
852
852
852
84
B2g
852
854
854
852
1.367e+38
0.8
1.879e+38
1.1
3.246e+38
1.9
85
Au
854
855
855
854
86
B1u
855
861
860
861
87
B1g
861
862
861
862
2.731e+38
1.6
3.755e+38
2.2
6.486e+38
3.8
88
B3g
862
874
862
904
2.577e+39
15.1
3.543e+39
20.7
6.120e+39
35.8
89
B3u
904
904
904
904
90
B2u
904
906
906
906
91
A1g
906
957
922
984
1.499e+40
87.7
5.047e+38
3.0
1.549e+40
90.6
92
B1g
984
984
984
987
5.801e+38
3.4
7.976e+38
4.7
1.378e+39
8.1
93
A1g
1086
1086
1086
1086
3.564e+39
20.9
1.709e+38
1.0
3.734e+39
21.9
94
B1g
1092
1092
1092
1092
4.754e+38
2.8
6.537e+38
3.8
1.129e+39
6.6
95
B2u
1122
1122
1131
1122
96
B3u
1131
1174
1185
1131
No.  Char.  ω TO  ω LOx  ω LOy  ω LOz  I ∥  I ⊥  I Total 
You can define the size of the supercell for the visualization of the vibration.
Nx: 
Ny: 
Nz: 
Normalized
Raw
Options for intensity.