-    CORDIERITE     -    Mg2Al4Si5O18

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:  66  Cccm 
Lattice parameters (Å):  17.0807  9.7307  9.3427 
Angles (°):  90  90  90 

Symmetry (theoretical): 

Space group:  66  Cccm 
Lattice parameters (Å):  9.6812  9.6812  9.2575 
Angles (°):  90  90  120.70 

Cell contents: 

Number of atoms:  56 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Mg:  0.3373  0.6627  0.2500 
Al:  0.5000  0.0000  0.2500 
Si:  0.5000  0.5000  0.2500 
Si:  0.2712  0.8850  0.0000 
Si:  0.8958  0.6250  0.0000 
Al:  0.3611  0.2581  0.0000 
O:  0.1451  0.6493  0.3582 
O:  0.6466  0.5202  0.3491 
O:  0.5139  0.8619  0.3580 
O:  0.7903  0.7044  0.0000 
O:  0.3092  0.0635  0.0000 
O:  0.0842  0.7551  0.0000 
Mg:  0.6627  0.3373  0.2500 
Si:  0.7288  0.1150  0.0000 
Si:  0.1042  0.3750  0.0000 
Al:  0.6389  0.7419  0.0000 
O:  0.8549  0.3507  0.3582 
O:  0.3534  0.4798  0.3491 
O:  0.4861  0.1381  0.3580 
O:  0.2097  0.2956  0.0000 
O:  0.6908  0.9365  0.0000 
O:  0.9158  0.2449  0.0000 
Al:  0.0000  0.5000  0.2500 
Si:  0.8850  0.2712  0.5000 
Si:  0.6250  0.8958  0.5000 
Al:  0.2581  0.3611  0.5000 
O:  0.6493  0.1451  0.1418 
O:  0.5202  0.6466  0.1509 
O:  0.8619  0.5139  0.1420 
O:  0.7044  0.7903  0.5000 
O:  0.0635  0.3092  0.5000 
O:  0.7551  0.0842  0.5000 
Si:  0.1150  0.7288  0.5000 
Si:  0.3750  0.1042  0.5000 
Al:  0.7419  0.6389  0.5000 
O:  0.3507  0.8549  0.1418 
O:  0.4798  0.3534  0.1509 
O:  0.1381  0.4861  0.1420 
O:  0.2956  0.2097  0.5000 
O:  0.9365  0.6908  0.5000 
O:  0.2449  0.9158  0.5000 
Mg:  0.6627  0.3373  0.7500 
Al:  0.5000  0.0000  0.7500 
Si:  0.5000  0.5000  0.7500 
O:  0.8549  0.3507  0.6418 
O:  0.3534  0.4798  0.6509 
O:  0.4861  0.1381  0.6420 
Mg:  0.3373  0.6627  0.7500 
O:  0.1451  0.6493  0.6418 
O:  0.6466  0.5202  0.6509 
O:  0.5139  0.8619  0.6420 
Al:  0.0000  0.5000  0.7500 
O:  0.3507  0.8549  0.8582 
O:  0.4798  0.3534  0.8491 
O:  0.1381  0.4861  0.8580 
O:  0.6493  0.1451  0.8582 
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
91
91
91
91
1.187e+38
1.2
1.632e+38
1.6
2.819e+38
2.8
5
B3g
92
92
92
92
2.954e+37
0.3
4.062e+37
0.4
7.017e+37
0.7
6
B1u
101
101
101
101
7
B2g
103
103
103
103
8
Au
104
104
104
104
9
B3g
118
118
118
118
10
B2u
119
119
119
119
11
B1g
120
120
120
120
3.067e+38
3.1
4.217e+38
4.2
7.283e+38
7.3
12
B2g
121
121
121
121
5.732e+37
0.6
7.882e+37
0.8
1.361e+38
1.4
13
A1g
127
127
127
127
3.882e+38
3.9
5.183e+37
0.5
4.400e+38
4.4
14
B3u
154
154
154
154
15
Ag
154
154
154
154
3.810e+38
3.8
2.119e+37
0.2
4.022e+38
4.0
16
B3g
155
155
155
155
1.436e+37
0.1
1.974e+37
0.2
3.410e+37
0.3
17
B1g
159
159
159
159
2.738e+36
0.0
3.764e+36
0.0
6.502e+36
0.1
18
B2u
164
164
164
164
19
B3u
166
166
166
166
20
B2u
167
167
168
167
21
B1u
168
168
168
170
22
B2g
171
171
171
171
1.389e+37
0.1
1.910e+37
0.2
3.299e+37
0.3
23
B1g
178
178
178
178
1.704e+36
0.0
2.343e+36
0.0
4.046e+36
0.0
24
Au
178
178
178
178
25
B2g
184
184
184
184
1.202e+36
0.0
1.653e+36
0.0
2.856e+36
0.0
26
B1u
185
185
185
185
27
B3u
187
188
187
187
28
B2u
188
188
189
188
29
Au
189
189
189
189
30
B3g
189
189
191
189
6.023e+36
0.1
8.282e+36
0.1
1.431e+37
0.1
31
B3g
194
194
194
194
2.411e+36
0.0
3.315e+36
0.0
5.725e+36
0.1
32
B1u
196
196
196
196
33
B2g
210
210
210
210
4.455e+37
0.4
6.125e+37
0.6
1.058e+38
1.1
34
Au
212
212
212
212
35
B3g
213
213
213
213
1.269e+37
0.1
1.745e+37
0.2
3.014e+37
0.3
36
A1g
236
236
236
236
8.566e+38
8.6
1.448e+37
0.1
8.711e+38
8.7
37
B1g
237
237
237
237
3.888e+37
0.4
5.345e+37
0.5
9.233e+37
0.9
38
B2g
238
238
238
238
1.018e+37
0.1
1.400e+37
0.1
2.419e+37
0.2
39
B1u
240
240
240
240
40
B2u
242
242
242
242
41
B1g
244
244
244
244
8.001e+37
0.8
1.100e+38
1.1
1.900e+38
1.9
42
B3u
245
245
245
245
43
B1u
252
252
252
254
44
Au
254
254
254
255
45
A1g
255
255
255
255
2.004e+39
20.1
6.134e+37
0.6
2.065e+39
20.7
46
B3u
255
256
255
256
47
B3g
256
256
256
257
2.170e+38
2.2
2.983e+38
3.0
5.153e+38
5.2
48
B2g
257
257
257
257
3.271e+38
3.3
4.498e+38
4.5
7.769e+38
7.8
49
B2u
261
261
261
261
50
B1g
269
269
269
269
7.002e+35
0.0
9.628e+35
0.0
1.663e+36
0.0
51
B3g
276
276
276
276
9.608e+37
1.0
1.321e+38
1.3
2.282e+38
2.3
52
B3u
285
285
285
285
53
Au
285
286
285
285
54
A1g
288
288
288
288
1.300e+39
13.0
1.135e+38
1.1
1.414e+39
14.2
55
B1g
291
291
291
291
56
B1g
294
294
294
294
1.057e+36
0.0
1.454e+36
0.0
2.511e+36
0.0
57
B2g
297
297
297
297
7.408e+37
0.7
1.019e+38
1.0
1.759e+38
1.8
58
B1u
300
300
300
301
59
A1g
301
301
301
301
3.565e+38
3.6
4.795e+37
0.5
4.045e+38
4.1
60
B2g
307
307
307
307
5.289e+36
0.1
7.273e+36
0.1
1.256e+37
0.1
61
A1g
317
317
317
317
1.595e+38
1.6
1.095e+38
1.1
2.690e+38
2.7
62
B3u
320
321
320
320
63
B3g
326
326
326
326
1.153e+38
1.2
1.585e+38
1.6
2.738e+38
2.7
64
Au
326
326
326
326
65
B2u
329
329
330
329
66
B2u
335
335
335
335
67
B1g
335
335
337
335
1.265e+36
0.0
1.740e+36
0.0
3.005e+36
0.0
68
B1u
344
344
344
345
69
B3u
352
352
352
352
70
B1g
352
352
352
352
1.454e+38
1.5
1.999e+38
2.0
3.452e+38
3.5
71
A1g
354
354
354
354
4.222e+38
4.2
4.468e+37
0.4
4.669e+38
4.7
72
B2u
356
356
357
356
73
B1u
361
361
361
362
74
Au
362
362
362
363
75
B3u
363
363
363
363
76
Ag
363
365
363
382
4.004e+38
4.0
2.508e+38
2.5
6.512e+38
6.5
77
B2u
382
382
385
387
78
B2g
387
387
387
388
1.075e+38
1.1
1.478e+38
1.5
2.552e+38
2.6
79
B3g
388
388
388
394
5.893e+36
0.1
8.103e+36
0.1
1.400e+37
0.1
80
B2u
394
394
394
394
81
B3u
394
395
394
400
82
B3g
400
400
400
409
4.543e+36
0.0
6.247e+36
0.1
1.079e+37
0.1
83
B1g
409
409
409
412
1.790e+37
0.2
2.461e+37
0.2
4.251e+37
0.4
84
B3u
412
421
412
421
85
A1g
421
421
421
422
6.771e+38
6.8
1.705e+38
1.7
8.476e+38
8.5
86
B2u
424
424
440
424
87
B3u
440
447
447
440
88
B1g
447
452
451
447
7.109e+37
0.7
9.775e+37
1.0
1.688e+38
1.7
89
B3g
452
454
452
452
6.877e+37
0.7
9.456e+37
0.9
1.633e+38
1.6
90
B2g
454
461
454
454
91
Au
461
468
461
461
92
B2g
468
470
468
468
1.646e+38
1.7
2.263e+38
2.3
3.909e+38
3.9
93
Au
470
472
470
470
94
B2u
472
472
472
472
2.206e+36
0.0
1.553e+36
0.0
3.759e+36
0.0
95
Ag
472
478
478
472
5.118e+37
0.5
3.481e+37
0.3
8.599e+37
0.9
96
B1u
478
485
485
484
97
B1g
485
486
486
485
3.486e+35
0.0
4.793e+35
0.0
8.279e+35
0.0
98
B1u
486
488
488
487
99
B2g
488
488
488
488
7.080e+38
7.1
9.735e+38
9.8
1.682e+39
16.9
100
B3g
488
496
494
488
9.665e+37
1.0
1.329e+38
1.3
2.295e+38
2.3
101
B2u
496
498
501
496
102
B1u
501
501
504
501
103
Au
524
524
524
524
104
B3u
525
525
525
525
105
B1g
536
536
536
536
7.748e+37
0.8
1.065e+38
1.1
1.840e+38
1.8
106
A1g
549
549
549
549
9.891e+39
99.2
7.657e+37
0.8
9.967e+39
100.0
107
B1g
558
558
558
558
5.062e+38
5.1
6.960e+38
7.0
1.202e+39
12.1
108
B3u
560
566
560
560
109
B1u
570
570
570
570
110
Au
572
572
572
572
111
B2u
573
573
575
573
112
A1g
575
575
584
575
5.153e+39
51.7
1.233e+38
1.2
5.276e+39
52.9
113
B1g
592
592
592
592
2.316e+36
0.0
3.185e+36
0.0
5.501e+36
0.1
114
B2u
593
593
596
593
115
Au
610
610
610
610
116
A1g
621
621
621
621
4.628e+38
4.6
5.655e+37
0.6
5.194e+38
5.2
117
B1u
623
623
623
623
118
B2g
623
623
623
636
3.343e+36
0.0
4.597e+36
0.0
7.940e+36
0.1
119
B2g
643
643
643
643
3.584e+37
0.4
4.928e+37
0.5
8.511e+37
0.9
120
B3g
646
646
646
646
4.192e+37
0.4
5.764e+37
0.6
9.956e+37
1.0
121
B2u
654
654
654
654
122
A1g
661
661
661
661
4.996e+39
50.1
2.947e+37
0.3
5.025e+39
50.4
123
B3u
670
676
670
670
124
B1g
685
685
685
685
6.112e+37
0.6
8.404e+37
0.8
1.452e+38
1.5
125
Au
689
689
689
689
126
B1u
699
699
699
699
127
B3u
702
703
702
702
128
A1g
709
709
709
709
6.829e+38
6.9
6.370e+36
0.1
6.893e+38
6.9
129
B1g
715
715
715
715
3.176e+37
0.3
4.367e+37
0.4
7.543e+37
0.8
130
A1g
717
717
717
717
5.279e+38
5.3
8.707e+37
0.9
6.150e+38
6.2
131
B1g
736
736
736
736
1.097e+37
0.1
1.508e+37
0.2
2.605e+37
0.3
132
B2g
738
738
738
738
2.313e+38
2.3
3.181e+38
3.2
5.494e+38
5.5
133
B2u
743
743
746
743
134
B3g
754
754
754
754
2.440e+38
2.4
3.354e+38
3.4
5.794e+38
5.8
135
B2u
763
763
763
763
136
B3u
763
782
792
763
137
B3g
800
800
800
800
4.289e+35
0.0
5.897e+35
0.0
1.019e+36
0.0
138
B3u
821
821
821
821
139
B2g
893
893
893
893
8.819e+37
0.9
1.213e+38
1.2
2.095e+38
2.1
140
B2g
894
894
894
894
4.698e+38
4.7
6.460e+38
6.5
1.116e+39
11.2
141
B3g
897
897
897
897
8.165e+37
0.8
1.123e+38
1.1
1.939e+38
1.9
142
B1u
900
900
900
901
143
Au
901
901
901
901
144
B2u
901
901
906
915
145
A1g
915
915
915
920
3.441e+38
3.5
1.263e+38
1.3
4.704e+38
4.7
146
B1u
928
928
928
946
147
B1g
946
946
946
946
3.764e+38
3.8
5.175e+38
5.2
8.938e+38
9.0
148
B2u
946
946
954
954
149
B3u
954
965
965
965
150
A1g
965
968
968
968
4.389e+39
44.0
8.677e+37
0.9
4.476e+39
44.9
151
B3u
968
970
970
970
152
B2g
970
973
973
973
2.202e+38
2.2
3.028e+38
3.0
5.229e+38
5.2
153
Au
973
975
975
975
154
B1g
975
979
979
979
4.411e+37
0.4
6.065e+37
0.6
1.048e+38
1.1
155
B3g
979
990
994
998
1.187e+38
1.2
1.632e+38
1.6
2.818e+38
2.8
156
B3g
998
998
998
1001
1.090e+37
0.1
1.499e+37
0.2
2.589e+37
0.3
157
B2u
1001
1001
1004
1004
158
A1g
1004
1004
1004
1011
2.268e+39
22.8
4.408e+38
4.4
2.709e+39
27.2
159
B1u
1012
1012
1012
1014
160
B1g
1014
1014
1014
1026
1.218e+38
1.2
1.674e+38
1.7
2.892e+38
2.9
161
B3u
1026
1034
1026
1055
162
Au
1055
1055
1055
1058
163
A1g
1117
1117
1117
1117
5.041e+38
5.1
7.217e+36
0.1
5.113e+38
5.1
164
B1g
1118
1118
1118
1118
1.464e+38
1.5
2.013e+38
2.0
3.477e+38
3.5
165
B2u
1136
1136
1137
1136
166
B3u
1142
1155
1142
1142
167
B2u
1155
1155
1159
1155
168
B1g
1163
1163
1163
1163
2.837e+37
0.3
3.900e+37
0.4
6.737e+37
0.7
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.