-    CUMMINGTONITE     -    Mg7Si8O22(OH)2

0GPa 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):  0.5292  0.5292  0.5292 
Angles (°):  84.26  95.73  55.13 

Cell contents: 

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

Atomic positions (theoretical):

Mg:  0.0855  0.0855  0.5000 
Mg:  0.1753  0.1753  0.0000 
Mg:  0.0000  0.0000  0.0000 
Mg:  0.2520  0.2520  0.5000 
Si:  0.3754  0.7938  0.2765 
Si:  0.4705  0.8713  0.7817 
O:  0.2003  0.9717  0.2109 
O:  0.2941  0.0507  0.7161 
O:  0.1153  0.8847  0.7094 
O:  0.6281  0.8696  0.7649 
O:  0.4892  0.7805  0.0705 
O:  0.4730  0.7639  0.5644 
O:  0.3497  0.6503  0.2652 
H:  0.2221  0.7779  0.7516 
Si:  0.7938  0.3754  0.7235 
Si:  0.8713  0.4705  0.2183 
O:  0.9717  0.2003  0.7891 
O:  0.0507  0.2941  0.2839 
O:  0.8847  0.1153  0.2906 
O:  0.8696  0.6281  0.2351 
O:  0.7805  0.4892  0.9295 
O:  0.7639  0.4730  0.4356 
O:  0.6503  0.3497  0.7348 
H:  0.7779  0.2221  0.2484 
Mg:  0.9145  0.9145  0.5000 
Mg:  0.8247  0.8247  0.0000 
Mg:  0.7480  0.7480  0.5000 
Si:  0.6246  0.2062  0.7235 
Si:  0.5295  0.1287  0.2183 
O:  0.7997  0.0283  0.7891 
O:  0.7059  0.9493  0.2839 
O:  0.3719  0.1304  0.2351 
O:  0.5108  0.2195  0.9295 
O:  0.5270  0.2361  0.4356 
Si:  0.2062  0.6246  0.2765 
Si:  0.1287  0.5295  0.7817 
O:  0.0283  0.7997  0.2109 
O:  0.9493  0.7059  0.7161 
O:  0.1304  0.3719  0.7649 
O:  0.2195  0.5108  0.0705 
O:  0.2361  0.5270  0.5644 
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
-56
-56
-56
-56
2
-39
-28
-39
-39
3
0
0
0
0
4
0
0
0
0
5
0
0
0
0
6
65
65
65
65
7
88
88
90
88
8
114
114
114
114
9
138
138
138
138
10
151
151
162
151
11
162
162
163
162
12
163
163
165
164
13
169
170
169
170
14
172
172
172
172
15
178
178
178
178
16
194
194
194
194
17
203
203
203
203
18
203
203
203
205
19
215
215
215
215
20
222
222
222
222
21
227
227
227
227
22
230
230
230
230
23
237
237
237
237
24
241
241
241
241
25
245
245
245
245
26
247
247
247
248
27
249
249
249
249
28
257
257
257
257
29
267
270
267
268
30
284
284
286
284
31
286
286
286
286
32
294
294
294
294
33
299
299
299
299
34
299
301
299
299
35
301
302
302
301
36
302
303
303
302
37
306
306
306
306
38
308
309
308
309
39
309
312
313
309
40
327
327
327
327
41
336
342
336
338
42
342
343
342
342
43
343
348
343
343
44
348
350
348
348
45
350
351
350
350
46
360
360
360
360
47
360
361
360
362
48
363
363
363
363
49
368
368
371
368
50
371
371
373
371
51
374
376
374
374
52
378
378
378
378
53
379
384
379
380
54
388
388
388
388
55
398
398
401
398
56
404
404
404
404
57
406
406
406
406
58
406
407
406
411
59
415
422
415
416
60
422
422
423
422
61
428
428
428
428
62
434
434
436
434
63
436
440
440
436
64
441
441
443
441
65
443
443
444
443
66
444
444
444
444
67
448
458
448
458
68
458
462
458
462
69
462
465
474
466
70
474
474
474
474
71
474
478
489
487
72
489
489
491
489
73
492
492
500
492
74
500
500
500
500
75
500
501
508
505
76
508
511
511
514
77
514
514
514
517
78
517
517
529
520
79
529
529
531
529
80
531
531
531
531
81
531
531
536
536
82
536
536
551
547
83
551
558
558
558
84
558
578
564
579
85
579
579
579
603
86
633
633
633
645
87
645
645
645
646
88
646
646
646
647
89
650
654
650
650
90
661
661
661
661
91
665
665
665
665
92
675
675
684
675
93
684
684
694
684
94
740
741
740
741
95
753
753
753
753
96
765
765
767
765
97
770
770
770
770
98
780
780
780
786
99
787
787
787
787
100
885
885
885
885
101
894
894
904
894
102
904
915
905
905
103
919
919
919
919
104
924
924
924
924
105
949
977
949
951
106
977
994
996
977
107
996
996
996
996
108
996
996
997
996
109
998
1002
998
1005
110
1005
1005
1008
1009
111
1009
1009
1009
1013
112
1016
1020
1016
1020
113
1020
1034
1020
1034
114
1034
1058
1034
1058
115
1058
1061
1061
1061
116
1061
1072
1062
1077
117
1077
1077
1087
1083
118
1087
1093
1093
1093
119
1093
1096
1110
1110
120
1110
1110
1124
1126
121
1126
1126
1165
1131
122
3661
3661
3661
3661
123
3661
3662
3661
3661
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.