-    JADEITE     -    NaAlSi2O6

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:  15  C2/c 
Lattice parameters (Å):  4.9871  4.5328  2.7645 
Angles (°):  90.0  107.6  90.0 

Symmetry (theoretical): 

Space group:  15  C2/c 
Lattice parameters (Å):  6.3780  6.3780  5.2369 
Angles (°):  90.0  108.0  90.0 

Cell contents: 

Number of atoms:  20 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Na:  0.2960  0.2960  0.2500 
Al:  0.9049  0.9049  0.2500 
Si:  0.3834  0.8029  0.2288 
O:  0.1847  0.9664  0.1271 
O:  0.6250  0.8995  0.2882 
O:  0.3524  0.6489  0.0145 
Si:  0.8029  0.3834  0.2712 
O:  0.9664  0.1847  0.3729 
O:  0.8995  0.6250  0.2118 
O:  0.6489  0.3524  0.4855 
Na:  0.7040  0.7040  0.7500 
Al:  0.0951  0.0951  0.7500 
Si:  0.6166  0.1971  0.7712 
O:  0.8153  0.0336  0.8729 
O:  0.3750  0.1005  0.7118 
O:  0.6476  0.3511  0.9855 
Si:  0.1971  0.6166  0.7288 
O:  0.0336  0.8153  0.6271 
O:  0.1005  0.3750  0.7882 
O:  0.3511  0.6476  0.5145 
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
Bg
122
122
122
122
9.326e+37
0.2
1.530e+38
0.4
2.463e+38
0.6
5
Bu
129
133
129
130
6
Ag
133
138
133
133
5.868e+38
1.5
2.264e+38
0.6
8.132e+38
2.1
7
Bu
168
172
168
171
8
Bg
174
174
174
174
2.940e+37
0.1
4.546e+37
0.1
7.486e+37
0.2
9
Ag
192
192
192
192
3.676e+39
9.6
8.694e+38
2.3
4.546e+39
11.9
10
Ag
195
195
195
195
1.259e+39
3.3
7.078e+38
1.9
1.967e+39
5.1
11
Bg
209
209
209
209
7.758e+38
2.0
8.632e+38
2.3
1.639e+39
4.3
12
Bu
226
226
226
229
13
Au
229
229
238
239
14
Bg
243
243
243
243
9.540e+38
2.5
1.541e+39
4.0
2.495e+39
6.5
15
Au
248
248
258
248
16
Ag
273
273
273
273
3.027e+39
7.9
1.520e+38
0.4
3.179e+39
8.3
17
Bu
276
278
276
277
18
Bg
288
288
288
288
1.867e+39
4.9
2.545e+39
6.7
4.412e+39
11.5
19
Au
302
302
303
302
20
Ag
312
312
312
312
5.528e+39
14.5
8.601e+38
2.2
6.388e+39
16.7
21
Bu
315
317
315
319
22
Au
319
319
319
319
23
Bg
324
324
324
324
1.072e+38
0.3
1.399e+38
0.4
2.471e+38
0.6
24
Bu
338
352
338
339
25
Ag
352
353
352
352
1.035e+40
27.1
5.237e+38
1.4
1.088e+40
28.5
26
Bg
353
363
353
353
3.462e+38
0.9
5.258e+38
1.4
8.720e+38
2.3
27
Ag
370
370
370
370
7.872e+39
20.6
9.167e+38
2.4
8.789e+39
23.0
28
Bg
372
372
372
372
1.107e+39
2.9
1.739e+39
4.5
2.846e+39
7.4
29
Bu
376
387
376
378
30
Au
394
394
394
394
31
Bg
402
402
402
402
7.658e+38
2.0
8.778e+38
2.3
1.644e+39
4.3
32
Au
407
407
413
407
33
Ag
413
413
424
413
4.318e+39
11.3
4.613e+37
0.1
4.364e+39
11.4
34
Bu
430
440
430
436
35
Bu
451
469
451
469
36
Au
469
477
492
492
37
Au
492
492
502
502
38
Ag
502
502
502
502
5.349e+39
14.0
1.743e+38
0.5
5.523e+39
14.4
39
Bg
502
502
529
534
6.874e+38
1.8
8.899e+38
2.3
1.577e+39
4.1
40
Bg
534
534
534
550
1.342e+38
0.4
2.216e+38
0.6
3.557e+38
0.9
41
Au
550
550
559
559
42
Ag
559
559
570
570
1.607e+39
4.2
6.299e+38
1.6
2.236e+39
5.9
43
Bu
570
574
574
574
44
Bg
574
609
603
588
5.532e+38
1.4
6.256e+38
1.6
1.179e+39
3.1
45
Bu
638
642
638
639
46
Ag
671
671
671
671
3.769e+40
98.6
5.372e+38
1.4
3.823e+40
100.0
47
Au
732
732
734
732
48
Bg
755
755
755
755
1.393e+39
3.6
1.875e+39
4.9
3.267e+39
8.5
49
Au
814
814
825
814
50
Bu
841
850
841
850
51
Bg
850
910
850
853
9.189e+38
2.4
1.053e+39
2.8
1.971e+39
5.2
52
Ag
954
954
954
954
7.354e+39
19.2
3.515e+39
9.2
1.087e+40
28.4
53
Bu
961
961
961
961
54
Ag
961
991
961
998
3.883e+39
10.2
7.872e+38
2.1
4.670e+39
12.2
55
Bg
998
998
998
1008
2.255e+38
0.6
2.405e+38
0.6
4.659e+38
1.2
56
Ag
1008
1008
1008
1010
1.976e+40
51.7
1.884e+39
4.9
2.165e+40
56.6
57
Au
1010
1010
1020
1012
58
Bu
1020
1039
1024
1039
59
Au
1039
1052
1052
1052
60
Bg
1052
1075
1152
1102
2.963e+38
0.8
4.378e+38
1.1
7.342e+38
1.9
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.