-    TOPAZ     -    Al2SiO4F2

Experimental structure 

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  Pbnm 
Lattice parameters (Å):  4.6499  8.7968  8.3909 
Angles (°):  90.0  90.0  90.0 

Symmetry (theoretical): 

Space group:  62  Pbnm 
Lattice parameters (Å):  4.6499  8.7968  8.3909 
Angles (°):  90.0  90.0  90.0 

Cell contents: 

Number of atoms:  36 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Al:  0.9035  0.1310  0.0824 
Si:  0.3978  0.9405  0.2500 
O:  0.7961  0.5321  0.2500 
O:  0.4569  0.7562  0.2500 
O:  0.7893  0.0106  0.9079 
F:  0.9018  0.7526  0.0572 
Al:  0.4035  0.3690  0.9176 
Si:  0.8978  0.5595  0.7500 
O:  0.2961  0.9679  0.7500 
O:  0.9569  0.7437  0.7500 
O:  0.2893  0.4894  0.0921 
F:  0.4018  0.7474  0.9428 
Al:  0.0965  0.8690  0.5824 
Si:  0.6022  0.0595  0.7500 
O:  0.2039  0.4679  0.7500 
O:  0.5431  0.2438  0.7500 
O:  0.2107  0.9894  0.4079 
F:  0.0982  0.2474  0.5572 
Al:  0.5965  0.6310  0.4176 
Si:  0.1022  0.4405  0.2500 
O:  0.7039  0.0321  0.2500 
O:  0.0431  0.2563  0.2500 
O:  0.7107  0.5106  0.5921 
F:  0.5982  0.2526  0.4428 
Al:  0.0965  0.8690  0.9176 
O:  0.2107  0.9894  0.0921 
F:  0.0982  0.2474  0.9428 
Al:  0.5965  0.6310  0.0824 
O:  0.7107  0.5106  0.9079 
F:  0.5982  0.2526  0.0572 
Al:  0.9035  0.1310  0.4176 
O:  0.7893  0.0106  0.5921 
F:  0.9018  0.7526  0.4428 
Al:  0.4035  0.3690  0.5824 
O:  0.2893  0.4894  0.4079 
F:  0.4018  0.7474  0.5572 
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
A1g
152
152
152
152
4.970e+38
3.0
7.534e+36
0.0
5.046e+38
3.0
5
B3g
162
162
162
162
9.424e+37
0.6
1.296e+38
0.8
2.238e+38
1.3
6
Au
167
167
167
167
7
B1u
177
177
177
177
8
B3u
180
181
180
180
9
B2g
181
182
181
181
9.701e+36
0.1
1.334e+37
0.1
2.304e+37
0.1
10
Au
182
182
182
182
11
B2u
206
206
206
206
12
B1g
229
229
229
229
2.050e+38
1.2
2.819e+38
1.7
4.869e+38
2.9
13
A1g
229
229
229
229
3.845e+39
22.9
1.418e+38
0.8
3.987e+39
23.8
14
Au
234
234
234
234
15
B2g
235
235
235
235
9.188e+36
0.1
1.263e+37
0.1
2.182e+37
0.1
16
B3g
242
242
242
242
1.530e+37
0.1
2.103e+37
0.1
3.633e+37
0.2
17
B1g
255
255
255
255
7.108e+37
0.4
9.774e+37
0.6
1.688e+38
1.0
18
B2u
259
259
261
259
19
A1g
261
261
262
261
1.184e+40
70.6
1.471e+38
0.9
1.199e+40
71.5
20
B1g
265
265
265
265
1.123e+38
0.7
1.544e+38
0.9
2.668e+38
1.6
21
A1g
272
272
272
272
8.965e+39
53.5
1.602e+38
1.0
9.125e+39
54.4
22
B3g
273
273
273
273
1.560e+38
0.9
2.145e+38
1.3
3.706e+38
2.2
23
B1u
277
277
277
279
24
Au
279
279
279
282
25
B2g
282
282
282
282
1.218e+37
0.1
1.675e+37
0.1
2.893e+37
0.2
26
B3u
285
286
285
285
27
Au
295
295
295
295
28
B2u
295
295
301
295
29
B3u
303
303
303
303
30
B3g
306
306
306
306
1.718e+38
1.0
2.362e+38
1.4
4.080e+38
2.4
31
A1g
318
318
318
318
2.596e+39
15.5
9.729e+37
0.6
2.693e+39
16.1
32
B1u
320
320
320
323
33
B3u
324
325
324
324
34
B1g
326
326
326
326
2.114e+36
0.0
2.907e+36
0.0
5.022e+36
0.0
35
B2g
339
339
339
339
1.369e+37
0.1
1.882e+37
0.1
3.251e+37
0.2
36
B1g
342
342
342
342
1.923e+38
1.1
2.644e+38
1.6
4.567e+38
2.7
37
B3g
346
346
346
346
2.093e+37
0.1
2.877e+37
0.2
4.970e+37
0.3
38
B1u
349
349
349
351
39
B2g
351
351
351
352
1.094e+38
0.7
1.505e+38
0.9
2.599e+38
1.6
40
B3u
355
357
355
355
41
B1g
362
362
362
362
7.349e+36
0.0
1.011e+37
0.1
1.745e+37
0.1
42
B2u
370
370
379
370
43
A1g
388
388
388
388
2.001e+39
11.9
7.921e+37
0.5
2.081e+39
12.4
44
B3g
403
403
403
403
4.518e+37
0.3
6.212e+37
0.4
1.073e+38
0.6
45
B2u
404
404
408
404
46
B2g
409
409
409
409
1.577e+37
0.1
2.169e+37
0.1
3.746e+37
0.2
47
B3u
417
419
417
417
48
Au
419
425
419
419
49
B1u
425
431
425
431
50
B2u
431
432
432
432
51
B2g
432
435
435
435
1.421e+36
0.0
1.954e+36
0.0
3.374e+36
0.0
52
A1g
435
440
440
439
1.776e+39
10.6
2.546e+38
1.5
2.031e+39
12.1
53
B1u
440
444
444
444
54
Au
444
449
448
449
55
B2u
449
450
450
450
56
B1g
450
450
452
452
1.527e+36
0.0
2.100e+36
0.0
3.627e+36
0.0
57
Au
452
452
454
454
58
B3u
454
454
454
454
59
B2g
454
458
460
460
1.277e+38
0.8
1.755e+38
1.0
3.032e+38
1.8
60
A1g
460
460
461
461
2.165e+38
1.3
2.708e+37
0.2
2.436e+38
1.5
61
B1g
461
461
463
463
5.804e+37
0.3
7.980e+37
0.5
1.378e+38
0.8
62
B3g
463
463
476
476
1.181e+38
0.7
1.624e+38
1.0
2.805e+38
1.7
63
B3g
476
476
482
479
9.284e+36
0.1
1.277e+37
0.1
2.205e+37
0.1
64
B3u
482
486
485
482
65
B1u
486
490
486
490
66
B3g
490
494
490
494
1.664e+37
0.1
2.288e+37
0.1
3.953e+37
0.2
67
A1g
494
514
494
500
8.159e+38
4.9
4.350e+38
2.6
1.251e+39
7.5
68
B1u
514
521
514
521
69
Au
521
525
521
525
70
B1g
525
527
525
527
1.577e+38
0.9
2.169e+38
1.3
3.746e+38
2.2
71
B2u
527
531
528
531
72
A1g
531
532
531
535
1.203e+39
7.2
1.262e+38
0.8
1.330e+39
7.9
73
B2g
543
543
543
543
5.882e+36
0.0
8.087e+36
0.0
1.397e+37
0.1
74
B3g
547
547
547
547
2.083e+37
0.1
2.864e+37
0.2
4.946e+37
0.3
75
B2u
548
548
550
548
76
B3u
550
550
551
550
77
B1g
551
551
554
551
4.542e+37
0.3
6.246e+37
0.4
1.079e+38
0.6
78
A1g
554
554
562
554
4.537e+37
0.3
2.664e+37
0.2
7.201e+37
0.4
79
B3u
563
564
563
563
80
Au
564
573
564
564
81
B2u
573
575
575
573
82
B1u
575
594
594
594
83
B1g
594
602
602
602
2.427e+37
0.1
3.336e+37
0.2
5.763e+37
0.3
84
B2g
602
612
612
612
3.602e+37
0.2
4.953e+37
0.3
8.554e+37
0.5
85
A1g
612
626
626
626
3.323e+38
2.0
7.331e+37
0.4
4.056e+38
2.4
86
B1u
626
626
633
635
87
B2g
635
635
635
636
8.350e+37
0.5
1.148e+38
0.7
1.983e+38
1.2
88
B1g
640
640
640
640
1.366e+36
0.0
1.878e+36
0.0
3.244e+36
0.0
89
Au
653
653
653
653
90
B2u
656
656
664
656
91
B3u
666
667
666
666
92
B3g
667
667
667
667
8.782e+37
0.5
1.208e+38
0.7
2.086e+38
1.2
93
B2u
809
809
809
809
94
A1g
809
809
810
809
2.741e+39
16.4
8.241e+38
4.9
3.565e+39
21.3
95
B1u
810
810
810
810
96
Au
810
810
826
826
97
B3u
826
843
846
846
98
B3u
846
856
856
856
99
B1g
856
863
858
863
2.815e+38
1.7
3.870e+38
2.3
6.685e+38
4.0
100
B2u
863
872
872
872
101
A1g
872
877
877
877
1.652e+40
98.5
2.475e+38
1.5
1.676e+40
100.0
102
B1g
877
887
886
887
4.022e+38
2.4
5.530e+38
3.3
9.552e+38
5.7
103
A1g
887
891
887
891
2.794e+39
16.7
1.429e+39
8.5
4.223e+39
25.2
104
B2u
891
933
934
934
105
B2g
934
934
955
955
1.598e+39
9.5
2.198e+39
13.1
3.796e+39
22.6
106
B3u
955
959
959
959
107
B3g
959
963
963
963
3.042e+38
1.8
4.183e+38
2.5
7.225e+38
4.3
108
B1g
963
1001
975
964
5.244e+38
3.1
7.211e+38
4.3
1.246e+39
7.4
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.