-    TALC     -    Mg3Si4O10(OH)2

 

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:  2  P-1 
Lattice parameters (Å):  5.2900  9.1730  9.4600 
Angles (°):  90.46  98.68  90.09 

Symmetry (theoretical): 

Space group:  2  P-1 
Lattice parameters (Å):  5.3307  10.2302  5.3298 
Angles (°):  98.26  119.99  85.60 

Cell contents: 

Number of atoms:  21 
Number of atom types:  4 
Chemical composition:  0 

Atomic positions (theoretical):

Mg:  0.0000  1.0000  0.0000 
Mg:  0.6667  1.0000  0.3335 
Mg:  0.3333  0.0000  0.6665 
Si:  0.0040  0.7294  0.2606 
Si:  0.6704  0.7294  0.5934 
Si:  0.9960  0.2706  0.7394 
Si:  0.3296  0.2706  0.4066 
O:  0.6681  0.8907  0.6362 
O:  0.3339  0.8976  0.9724 
O:  0.0024  0.8907  0.3048 
O:  0.8497  0.6748  0.9122 
O:  0.8263  0.6743  0.4005 
O:  0.3379  0.6743  0.4238 
O:  0.3319  0.1093  0.3638 
O:  0.6661  0.1024  0.0276 
O:  0.9976  0.1093  0.6952 
O:  0.1503  0.3252  0.0878 
O:  0.1737  0.3257  0.5995 
O:  0.6621  0.3257  0.5762 
H:  0.3332  0.8028  0.9467 
H:  0.6668  0.1972  0.0533 
Atom type  X  Y  Z 

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.

Choose the polarization of the lasers.

I ∥ 
I ⊥ 
I Total 
Horizontal:
Xmin:
Xmax:
Vertical:
Ymin:
Ymax:
 

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
Ag
100
100
100
100
7.680e+38
1.7
9.933e+38
2.2
1.761e+39
3.9
5
Ag
102
102
102
102
9.628e+38
2.1
1.106e+39
2.4
2.069e+39
4.6
6
Au
146
146
146
146
7
Ag
146
146
146
146
3.261e+38
0.7
6.859e+37
0.2
3.947e+38
0.9
8
Au
159
161
159
159
9
Ag
169
169
169
169
3.388e+40
74.5
3.183e+39
7.0
3.706e+40
81.5
10
Au
170
170
170
171
11
Ag
222
222
222
222
3.855e+38
0.8
4.503e+38
1.0
8.358e+38
1.8
12
Au
226
226
226
226
13
Au
240
240
242
240
14
Ag
283
283
283
283
3.661e+39
8.1
2.234e+38
0.5
3.884e+39
8.5
15
Ag
286
286
286
286
2.423e+38
0.5
2.047e+38
0.5
4.469e+38
1.0
16
Au
287
287
287
288
17
Au
295
296
296
295
18
Ag
312
312
312
312
3.584e+38
0.8
4.448e+38
1.0
8.031e+38
1.8
19
Ag
312
312
312
312
4.324e+38
1.0
3.869e+38
0.9
8.194e+38
1.8
20
Au
331
331
331
332
21
Ag
336
336
336
336
6.807e+37
0.1
8.052e+37
0.2
1.486e+38
0.3
22
Ag
346
346
346
346
1.181e+40
26.0
1.550e+38
0.3
1.197e+40
26.3
23
Au
355
357
356
355
24
Au
357
358
357
357
25
Au
360
361
360
360
26
Ag
365
365
365
365
3.791e+38
0.8
2.697e+38
0.6
6.488e+38
1.4
27
Ag
366
366
366
366
6.240e+38
1.4
1.266e+38
0.3
7.506e+38
1.7
28
Au
373
373
373
380
29
Au
393
395
398
393
30
Ag
405
405
405
405
3.074e+39
6.8
3.634e+38
0.8
3.438e+39
7.6
31
Ag
406
406
406
406
4.727e+38
1.0
6.009e+38
1.3
1.074e+39
2.4
32
Au
415
416
416
416
33
Au
416
422
417
421
34
Ag
422
431
422
422
4.658e+38
1.0
6.846e+38
1.5
1.150e+39
2.5
35
Au
431
439
432
439
36
Ag
439
469
439
469
2.537e+39
5.6
7.451e+38
1.6
3.282e+39
7.2
37
Au
469
479
477
479
38
Ag
479
486
479
486
2.429e+38
0.5
3.184e+38
0.7
5.613e+38
1.2
39
Au
486
488
486
488
40
Ag
488
489
488
490
2.762e+38
0.6
1.595e+38
0.4
4.357e+38
1.0
41
Au
490
540
518
540
42
Au
576
577
576
576
43
Au
577
585
577
585
44
Ag
585
585
585
585
1.021e+39
2.2
1.302e+39
2.9
2.322e+39
5.1
45
Ag
585
593
585
596
9.581e+38
2.1
1.264e+39
2.8
2.222e+39
4.9
46
Ag
636
636
636
636
4.544e+40
99.9
2.274e+37
0.1
4.547e+40
100.0
47
Au
656
656
657
656
48
Au
738
738
738
738
49
Ag
739
739
739
739
7.106e+38
1.6
6.307e+38
1.4
1.341e+39
2.9
50
Au
741
741
741
741
51
Ag
742
742
742
742
7.374e+38
1.6
9.845e+38
2.2
1.722e+39
3.8
52
Ag
830
830
830
830
53
Au
830
830
830
830
6.751e+35
0.0
6.886e+35
0.0
1.364e+36
0.0
54
Au
884
884
919
884
55
Ag
920
920
920
920
56
Au
920
920
920
920
6.330e+38
1.4
7.906e+38
1.7
1.424e+39
3.1
57
Ag
920
920
920
920
58
Au
920
976
976
976
6.217e+38
1.4
9.043e+38
2.0
1.526e+39
3.4
59
Ag
976
1009
979
1009
5.194e+39
11.4
1.239e+39
2.7
6.433e+39
14.1
60
Ag
1009
1009
1009
1009
61
Au
1009
1060
1009
1059
62
Au
3752
3752
3752
3752
63
Ag
3752
3752
3754
3752
2.176e+40
47.9
5.480e+38
1.2
2.231e+40
49.1
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.