-    CUMMINGTONITE     -    Mg7Si8O22(OH)2

2GPa under construction 

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:  12  C2/m 
Lattice parameters (Å):  9.5015  18.1289  5.3089 
Angles (°):  90  102.090  90 

Symmetry (theoretical): 

Space group:  12  C2/m 
Lattice parameters (Å):  9.9550  9.9550  5.1782 
Angles (°):  83.88  96.11  55.18 

Cell contents: 

Number of atoms:  41 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Mg:  0.0852  0.0852  0.5000 
Mg:  0.1748  0.1748  1.0000 
Mg:  1.0000  1.0000  1.0000 
Mg:  0.2522  0.2522  0.5000 
Si:  0.3778  0.7907  0.2858 
Si:  0.4716  0.8694  0.7905 
O:  0.2015  0.9699  0.2134 
O:  0.2937  0.0498  0.7199 
O:  0.1169  0.8831  0.7128 
O:  0.6273  0.8702  0.7608 
O:  0.4977  0.7823  0.0925 
O:  0.4687  0.7567  0.5860 
O:  0.3534  0.6466  0.2558 
H:  0.2247  0.7753  0.7578 
Si:  0.7907  0.3778  0.7142 
Si:  0.8694  0.4716  0.2095 
O:  0.9699  0.2015  0.7866 
O:  0.0498  0.2937  0.2801 
O:  0.8831  0.1169  0.2872 
O:  0.8702  0.6273  0.2392 
O:  0.7823  0.4977  0.9075 
O:  0.7567  0.4687  0.4140 
O:  0.6466  0.3534  0.7442 
H:  0.7753  0.2247  0.2422 
Mg:  0.9148  0.9148  0.5000 
Mg:  0.8252  0.8252  1.0000 
Mg:  0.7478  0.7478  0.5000 
Si:  0.6222  0.2093  0.7142 
Si:  0.5284  0.1306  0.2095 
O:  0.7985  0.0301  0.7866 
O:  0.7063  0.9502  0.2801 
O:  0.3727  0.1298  0.2392 
O:  0.5023  0.2177  0.9075 
O:  0.5313  0.2433  0.4140 
Si:  0.2093  0.6222  0.2858 
Si:  0.1306  0.5284  0.7905 
O:  0.0301  0.7985  0.2134 
O:  0.9502  0.7063  0.7199 
O:  0.1298  0.3727  0.7608 
O:  0.2177  0.5023  0.0925 
O:  0.2433  0.5313  0.5860 
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
-39
-39
-39
-39
2
0
0
0
0
3
0
0
0
0
4
0
0
0
0
5
76
80
76
76
6
98
98
98
98
7
103
103
104
103
8
117
117
117
117
9
143
143
143
143
10
156
156
165
156
11
165
165
165
165
12
165
165
169
165
13
173
173
173
173
14
180
180
180
180
15
185
185
185
185
16
197
197
197
197
17
208
209
208
210
18
212
212
212
212
19
230
230
230
230
20
233
233
233
233
21
234
234
234
234
22
235
235
235
235
23
247
247
247
247
24
251
251
251
251
25
255
255
255
255
26
255
255
255
255
27
257
257
257
257
28
261
261
261
261
29
268
273
268
271
30
285
285
285
285
31
291
291
293
291
32
297
297
300
297
33
304
304
304
304
34
304
307
304
304
35
309
309
309
309
36
310
310
310
310
37
310
310
310
310
38
311
315
311
313
39
315
318
318
315
40
332
332
332
332
41
343
351
343
346
42
351
352
351
351
43
352
357
352
352
44
359
359
359
359
45
362
362
362
362
46
369
371
369
370
47
373
373
373
373
48
374
374
374
374
49
377
377
381
377
50
381
381
381
381
51
383
388
383
384
52
389
389
389
389
53
393
393
393
394
54
402
402
402
402
55
409
409
411
409
56
414
414
414
414
57
415
415
415
415
58
418
418
418
420
59
427
429
427
429
60
429
432
430
430
61
434
434
434
434
62
443
443
447
443
63
447
452
450
448
64
452
453
455
452
65
457
457
457
457
66
457
457
457
457
67
459
465
459
465
68
465
470
465
470
69
470
477
478
476
70
478
478
486
478
71
486
489
496
496
72
496
496
498
498
73
498
498
505
498
74
505
505
507
505
75
507
507
516
516
76
516
521
520
522
77
522
522
522
527
78
529
529
541
529
79
541
541
543
541
80
543
543
543
543
81
543
543
545
543
82
545
546
571
561
83
571
576
574
576
84
576
587
576
587
85
587
596
587
612
86
638
639
638
652
87
652
652
652
655
88
655
655
655
657
89
658
662
658
658
90
671
671
671
671
91
674
674
674
674
92
681
681
690
681
93
690
690
701
690
94
753
753
753
754
95
764
764
764
764
96
767
767
770
767
97
782
782
782
782
98
792
792
792
792
99
794
794
794
800
100
897
897
897
897
101
905
905
915
905
102
916
926
916
917
103
931
931
931
931
104
932
932
932
932
105
958
986
958
959
106
986
993
995
986
107
995
995
996
995
108
996
999
997
999
109
999
1003
999
1003
110
1003
1012
1014
1014
111
1014
1014
1016
1024
112
1025
1029
1025
1029
113
1029
1045
1029
1045
114
1045
1050
1045
1050
115
1050
1052
1052
1052
116
1052
1072
1058
1076
117
1077
1082
1077
1082
118
1082
1084
1084
1084
119
1084
1095
1102
1102
120
1102
1102
1123
1123
121
1123
1123
1164
1125
122
3656
3656
3656
3656
123
3656
3657
3656
3656
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.