-    NORBERGITE     -    Mg3SiO4F2

The crystal structure is fully relaxed (both unit cell parameters and atomic positions under symmetry constraints) starting from an experimental structure similar to the one reported in 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  Pbnm 
Lattice parameters (Å):  4.7104  10.2718  8.7476 
Angles (°):  90  90  90 

Symmetry (theoretical): 

Space group:  62  Pbnm 
Lattice parameters (Å):  4.6341  10.0634  8.5658 
Angles (°):  90  90  90 

Cell contents: 

Number of atoms:  40 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Mg:  0.9910  0.6321  0.4299 
Mg:  0.9929  0.9059  0.2500 
Si:  0.4205  0.7199  0.2500 
O:  0.7651  0.7210  0.2500 
O:  0.2768  0.5729  0.2500 
O:  0.2665  0.7919  0.1021 
F:  0.7268  0.9666  0.0849 
Mg:  0.4910  0.8679  0.5701 
Mg:  0.4929  0.5941  0.7500 
Si:  0.9205  0.7801  0.7500 
O:  0.2651  0.7790  0.7500 
O:  0.7768  0.9271  0.7500 
O:  0.7665  0.7081  0.8979 
F:  0.2268  0.5334  0.9151 
Mg:  0.0090  0.3679  0.9299 
Mg:  0.0071  0.0941  0.7500 
Si:  0.5795  0.2801  0.7500 
O:  0.2349  0.2790  0.7500 
O:  0.7232  0.4271  0.7500 
O:  0.7335  0.2081  0.6021 
F:  0.2732  0.0334  0.5849 
Mg:  0.5090  0.1321  0.0701 
Mg:  0.5071  0.4059  0.2500 
Si:  0.0795  0.2199  0.2500 
O:  0.7349  0.2210  0.2500 
O:  0.2232  0.0729  0.2500 
O:  0.2335  0.2919  0.3979 
F:  0.7732  0.4666  0.4151 
Mg:  0.0090  0.3679  0.5701 
O:  0.7335  0.2081  0.8979 
F:  0.2732  0.0334  0.9151 
Mg:  0.5090  0.1321  0.4299 
O:  0.2335  0.2919  0.1021 
F:  0.7732  0.4666  0.0849 
Mg:  0.9910  0.6321  0.0701 
O:  0.2665  0.7919  0.3979 
F:  0.7268  0.9666  0.4151 
Mg:  0.4910  0.8679  0.9299 
O:  0.7665  0.7081  0.6021 
F:  0.2268  0.5334  0.5849 
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
B2g
111
111
111
111
5
A1g
124
124
124
124
3.845e+37
0.1
2.881e+37
0.1
6.726e+37
0.1
6
A1g
157
157
157
157
4.361e+37
0.1
2.578e+37
0.0
6.939e+37
0.1
7
Au
158
158
158
158
8
Au
162
162
162
162
9
B1g
162
162
162
162
10
B2u
173
173
173
173
11
B1u
173
173
173
175
12
B3g
176
176
176
176
3.081e+36
0.0
4.237e+36
0.0
7.318e+36
0.0
13
Au
182
182
182
182
14
B3u
182
184
182
182
15
B2g
184
188
184
184
1.750e+37
0.0
2.407e+37
0.0
4.157e+37
0.1
16
B1u
203
203
203
204
17
B2g
204
204
204
210
1.812e+37
0.0
2.492e+37
0.0
4.304e+37
0.1
18
B3g
213
213
213
213
5.277e+37
0.1
7.255e+37
0.1
1.253e+38
0.2
19
B1u
215
215
215
217
20
B1g
217
217
217
219
4.819e+37
0.1
6.626e+37
0.1
1.145e+38
0.2
21
A1g
222
222
222
222
7.256e+38
1.4
6.610e+37
0.1
7.917e+38
1.5
22
B3u
225
227
225
225
23
B2u
231
231
232
231
24
B1g
232
232
232
232
2.124e+37
0.0
2.921e+37
0.1
5.046e+37
0.1
25
B2u
241
241
241
241
26
B2g
244
244
244
244
1.294e+38
0.3
1.780e+38
0.3
3.074e+38
0.6
27
B3g
245
245
245
245
8.387e+36
0.0
1.153e+37
0.0
1.992e+37
0.0
28
A1g
257
257
257
257
1.938e+38
0.4
1.446e+38
0.3
3.384e+38
0.7
29
B3g
262
262
262
262
1.276e+37
0.0
1.755e+37
0.0
3.031e+37
0.1
30
Au
263
263
263
263
31
B3u
265
267
265
265
32
B3g
274
274
274
274
3.154e+36
0.0
4.336e+36
0.0
7.490e+36
0.0
33
B2g
275
275
275
275
4.523e+36
0.0
6.219e+36
0.0
1.074e+37
0.0
34
B1g
276
276
276
276
4.402e+37
0.1
6.053e+37
0.1
1.046e+38
0.2
35
B2u
287
287
287
287
36
Au
288
288
288
288
37
B1g
294
294
294
294
1.452e+38
0.3
1.996e+38
0.4
3.448e+38
0.7
38
A1g
297
297
297
297
2.878e+38
0.6
8.112e+36
0.0
2.960e+38
0.6
39
B3u
299
300
299
299
40
B1u
303
303
303
304
41
Au
306
306
306
306
42
B3g
310
310
310
310
1.908e+37
0.0
2.623e+37
0.1
4.531e+37
0.1
43
B3u
318
322
318
318
44
Au
322
325
322
322
45
B2u
328
328
329
328
46
B1u
329
329
338
330
47
B2g
338
338
339
338
6.141e+36
0.0
8.443e+36
0.0
1.458e+37
0.0
48
B1g
339
339
340
339
1.109e+38
0.2
1.524e+38
0.3
2.633e+38
0.5
49
A1g
340
340
347
340
4.533e+38
0.9
1.511e+38
0.3
6.043e+38
1.2
50
A1g
347
347
351
347
4.089e+38
0.8
5.326e+37
0.1
4.621e+38
0.9
51
B2g
351
351
352
351
5.641e+37
0.1
7.756e+37
0.1
1.340e+38
0.3
52
B3g
354
354
354
354
2.199e+38
0.4
3.023e+38
0.6
5.222e+38
1.0
53
B3u
361
363
361
361
54
Ag
364
364
364
364
6.747e+37
0.1
9.277e+37
0.2
1.602e+38
0.3
55
B1u
364
364
364
364
56
Ag
364
364
364
364
6.745e+37
0.1
9.274e+37
0.2
1.602e+38
0.3
57
A1g
377
377
377
377
2.257e+38
0.4
6.985e+37
0.1
2.956e+38
0.6
58
B2u
380
380
380
380
59
B3u
381
381
381
381
60
Au
381
381
381
381
5.958e+36
0.0
8.192e+36
0.0
1.415e+37
0.0
61
B1g
381
381
381
381
1.579e+36
0.0
2.171e+36
0.0
3.750e+36
0.0
62
B1u
386
386
386
392
63
B3g
392
392
392
404
6.443e+38
1.2
8.859e+38
1.7
1.530e+39
3.0
64
Au
404
404
404
404
65
B2u
404
404
406
406
66
B2g
406
406
410
409
3.138e+37
0.1
4.315e+37
0.1
7.453e+37
0.1
67
B1u
410
410
410
410
68
B1g
410
410
415
415
1.820e+37
0.0
2.502e+37
0.0
4.322e+37
0.1
69
B3u
415
424
422
424
70
B3g
424
427
424
427
3.355e+38
0.6
4.613e+38
0.9
7.968e+38
1.5
71
Au
427
427
427
427
72
A1g
427
429
427
429
3.159e+38
0.6
1.346e+38
0.3
4.504e+38
0.9
73
B3u
429
430
429
429
74
B1u
430
437
430
437
75
B1g
437
438
437
438
1.421e+37
0.0
1.954e+37
0.0
3.375e+37
0.1
76
B2u
438
443
444
444
77
A1g
444
444
446
445
2.036e+39
3.9
1.246e+38
0.2
2.161e+39
4.2
78
B3u
446
450
448
446
79
B2u
450
452
452
450
80
B2g
452
453
453
452
7.205e+36
0.0
9.907e+36
0.0
1.711e+37
0.0
81
B3g
453
454
454
453
2.380e+37
0.0
3.273e+37
0.1
5.653e+37
0.1
82
A1g
454
456
456
454
1.342e+39
2.6
1.397e+38
0.3
1.481e+39
2.9
83
B1g
456
477
477
456
3.461e+38
0.7
4.759e+38
0.9
8.221e+38
1.6
84
B2g
477
482
482
477
2.346e+37
0.0
3.226e+37
0.1
5.573e+37
0.1
85
Au
482
485
483
482
86
B3g
485
489
485
485
1.886e+38
0.4
2.593e+38
0.5
4.478e+38
0.9
87
B1u
489
490
489
490
88
A1g
490
490
490
490
1.407e+38
0.3
9.863e+37
0.2
2.393e+38
0.5
89
B1g
490
492
490
492
1.160e+37
0.0
1.594e+37
0.0
2.754e+37
0.1
90
B2g
492
493
492
495
3.179e+38
0.6
4.371e+38
0.8
7.550e+38
1.5
91
B2u
495
495
525
525
92
B3u
525
545
533
543
93
B1u
548
548
548
551
94
A1g
551
551
551
555
4.639e+38
0.9
2.342e+38
0.5
6.982e+38
1.3
95
B2g
555
555
555
562
2.325e+37
0.0
3.197e+37
0.1
5.523e+37
0.1
96
B2u
562
562
563
563
97
Au
563
563
572
572
98
B3g
572
572
574
574
3.702e+38
0.7
5.090e+38
1.0
8.792e+38
1.7
99
B3u
574
575
582
575
100
B1g
582
582
592
582
7.464e+38
1.4
1.026e+39
2.0
1.773e+39
3.4
101
A1g
613
613
613
613
7.512e+39
14.5
5.799e+38
1.1
8.092e+39
15.6
102
B3u
614
641
614
614
103
B1g
641
645
641
641
5.939e+36
0.0
8.166e+36
0.0
1.411e+37
0.0
104
B2u
645
669
645
645
105
A1g
842
842
842
842
5.137e+40
99.3
3.841e+38
0.7
5.176e+40
100.0
106
B3u
845
847
845
845
107
B2u
851
851
852
851
108
B1g
856
856
856
856
2.633e+37
0.1
3.620e+37
0.1
6.252e+37
0.1
109
B1u
877
877
877
881
110
B2g
881
881
881
894
1.851e+39
3.6
2.545e+39
4.9
4.396e+39
8.5
111
A1g
894
894
894
897
1.556e+39
3.0
1.088e+39
2.1
2.644e+39
5.1
112
B2u
897
897
930
930
113
Au
930
930
936
936
114
B3u
936
938
949
949
115
B3g
949
949
956
956
7.181e+38
1.4
9.874e+38
1.9
1.706e+39
3.3
116
B1g
956
956
975
966
9.485e+38
1.8
1.304e+39
2.5
2.253e+39
4.4
117
A1g
976
976
976
976
3.090e+39
6.0
1.999e+39
3.9
5.088e+39
9.8
118
B3u
976
985
976
976
119
B1g
985
988
985
985
7.550e+37
0.1
1.038e+38
0.2
1.793e+38
0.3
120
B2u
988
1054
989
988
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.