-    CRYOLITE     -    Na3AlF6

 

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:  14  P2_1/c 
Lattice parameters (Å):  5.4024  5.5959  7.7564 
Angles (°):  90  90.27  90 

Symmetry (theoretical): 

Space group:  14  P2_1/c 
Lattice parameters (Å):  5.4024  5.5959  7.7564 
Angles (°):  90  90.27  90 

Cell contents: 

Number of atoms:  20 
Number of atom types:  3 
Chemical composition:  0 

Atomic positions (theoretical):

Na:  0.0000  0.0000  0.0000 
Na:  0.0000  0.0000  0.5000 
Al:  0.5245  0.9937  0.2503 
F:  0.2128  0.0361  0.2500 
F:  0.6329  0.1569  0.0798 
F:  0.1331  0.3429  0.9213 
Na:  0.5000  0.5000  0.5000 
Na:  0.5000  0.5000  0.0000 
Al:  0.9755  0.4937  0.2497 
F:  0.2872  0.5361  0.2500 
F:  0.8671  0.6569  0.4202 
F:  0.3669  0.8429  0.5787 
Al:  0.4755  0.0063  0.7497 
F:  0.7872  0.9639  0.7500 
F:  0.3671  0.8431  0.9202 
F:  0.8669  0.6571  0.0787 
Al:  0.0245  0.5063  0.7503 
F:  0.7128  0.4639  0.7500 
F:  0.1329  0.3431  0.5798 
F:  0.6331  0.1571  0.4213 
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
Bu
-124
-110
-124
-124
2
Bu
-65
-62
-65
-65
3
Bg
-62
-55
-61
-62
4
Ac
0
0
0
0
5
Ac
0
0
0
0
6
Ac
0
0
0
0
7
Au
10
10
10
10
8
Bg
45
45
45
45
9
Bu
62
63
62
67
10
Bg
70
70
71
70
11
Bg
84
84
84
84
12
Ag
87
87
87
87
1.354e+47
20.1
8.353e+45
1.2
1.437e+47
21.3
13
Bu
90
90
90
90
14
Ag
107
107
107
107
1.003e+46
1.5
2.787e+45
0.4
1.282e+46
1.9
15
Bg
117
117
117
117
1.768e+44
0.0
2.308e+44
0.0
4.075e+44
0.1
16
Au
117
117
118
117
17
Au
126
126
126
126
2.172e+47
32.2
2.929e+47
43.4
5.101e+47
75.6
18
Bg
129
129
129
129
19
Ag
146
146
146
146
2.160e+47
32.0
5.396e+45
0.8
2.214e+47
32.8
20
Au
156
156
156
156
2.723e+47
40.4
4.024e+47
59.6
6.747e+47
100.0
21
Bg
161
161
161
161
22
Bu
162
163
162
162
23
Ag
170
170
170
170
7.227e+44
0.1
5.384e+44
0.1
1.261e+45
0.2
24
Bg
186
186
186
186
25
Ag
186
186
186
186
2.769e+45
0.4
4.619e+44
0.1
3.231e+45
0.5
26
Au
190
190
190
190
1.876e+44
0.0
2.580e+44
0.0
4.456e+44
0.1
27
Bu
191
191
191
191
28
Bu
194
195
194
194
29
Au
206
206
206
206
4.122e+46
6.1
4.957e+46
7.3
9.079e+46
13.5
30
Ag
219
219
219
219
6.722e+46
10.0
8.905e+45
1.3
7.612e+46
11.3
31
Bg
221
221
221
221
32
Bu
225
225
225
225
33
Au
227
227
227
227
3.301e+44
0.0
5.561e+44
0.1
8.862e+44
0.1
34
Bu
232
232
232
233
35
Ag
235
235
235
235
2.483e+45
0.4
1.186e+45
0.2
3.669e+45
0.5
36
Bg
255
255
255
255
37
Ag
257
257
257
257
1.053e+45
0.2
1.328e+45
0.2
2.381e+45
0.4
38
Au
264
264
264
264
3.151e+44
0.0
3.375e+44
0.1
6.527e+44
0.1
39
Ag
267
267
267
267
3.183e+45
0.5
2.308e+45
0.3
5.491e+45
0.8
40
Bg
270
270
270
270
41
Bg
278
278
279
278
42
Bu
279
279
279
279
43
Au
282
282
282
282
5.247e+46
7.8
8.193e+46
12.1
1.344e+47
19.9
44
Bu
283
295
283
283
45
Bg
326
326
327
326
46
Bu
330
330
330
330
47
Bu
332
332
332
332
48
Bg
333
333
334
333
49
Bu
462
475
462
462
50
Au
486
486
486
486
1.441e+46
2.1
2.297e+46
3.4
3.738e+46
5.5
51
Bg
523
523
525
523
52
Ag
543
543
543
543
2.609e+45
0.4
1.827e+45
0.3
4.436e+45
0.7
53
Bg
591
591
591
591
54
Bu
598
598
598
602
55
Ag
619
619
619
619
2.067e+46
3.1
2.848e+46
4.2
4.915e+46
7.3
56
Au
619
619
619
619
2.170e+44
0.0
5.783e+43
0.0
2.748e+44
0.0
57
Bu
630
633
630
630
58
Ag
638
638
638
638
2.296e+45
0.3
9.867e+44
0.1
3.282e+45
0.5
59
Bg
659
659
659
659
60
Au
660
660
660
660
2.702e+43
0.0
4.025e+43
0.0
6.726e+43
0.0
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.