-    NEPHELINE-Na     -    NaAlSiO4

 

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:  173  P6_3 
Lattice parameters (Å):  5.1520  5.1520  8.6621 
Angles (°):  90.0  90  120 

Symmetry (theoretical): 

Space group:  173  P6_3 
Lattice parameters (Å):  5.1520  5.1520  8.6621 
Angles (°):  90  90  120 

Cell contents: 

Number of atoms:  14 
Number of atom types:  4 
Chemical composition:  0 

Atomic positions (theoretical):

Na:  0.0000  0.0000  0.2429 
Al:  0.3333  0.6667  0.0561 
Si:  0.3333  0.6667  0.4396 
O:  0.3333  0.6667  0.2540 
O:  0.6200  0.0142  0.9978 
Na:  0.0000  0.0000  0.7429 
Al:  0.6667  0.3333  0.5561 
Si:  0.6667  0.3333  0.9396 
O:  0.6667  0.3333  0.7540 
O:  0.6058  0.6200  0.4978 
O:  0.9858  0.6058  0.9978 
O:  0.3800  0.9858  0.4978 
O:  0.3942  0.3800  0.9978 
O:  0.0142  0.3942  0.4978 
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
-102
-102
-102
-94
2
-94
-94
-94
-94
3
-94
-65
-65
-61
4
-61
-61
-61
-61
5
-61
-61
-61
0
6
0
0
0
0
7
0
0
0
0
8
0
0
0
47
9
47
47
47
47
1.587e+37
0.0
1.667e+37
0.0
3.254e+37
0.1
10
47
47
47
54
1.588e+37
0.0
1.706e+37
0.0
3.294e+37
0.1
11
59
59
59
59
12
81
81
81
81
6.480e+38
1.2
7.246e+38
1.3
1.373e+39
2.5
13
81
126
126
81
6.480e+38
1.2
1.057e+39
1.9
1.705e+39
3.1
14
211
211
211
211
2.682e+38
0.5
3.336e+38
0.6
6.018e+38
1.1
15
211
211
211
211
2.682e+38
0.5
2.364e+38
0.4
5.046e+38
0.9
16
266
266
266
266
17
301
301
301
301
4.115e+37
0.1
4.611e+37
0.1
8.725e+37
0.2
18
301
301
301
301
4.115e+37
0.1
4.133e+37
0.1
8.248e+37
0.1
19
312
312
312
312
20
320
320
320
321
5.482e+40
98.8
6.747e+38
1.2
5.550e+40
100.0
21
356
356
356
356
1.409e+38
0.3
2.377e+38
0.4
3.785e+38
0.7
22
356
361
361
356
1.409e+38
0.3
1.497e+38
0.3
2.906e+38
0.5
23
421
421
421
423
1.253e+39
2.3
2.884e+38
0.5
1.541e+39
2.8
24
423
423
423
435
25
435
435
435
435
3.740e+38
0.7
4.137e+38
0.7
7.878e+38
1.4
26
435
438
438
438
3.740e+38
0.7
6.149e+38
1.1
9.889e+38
1.8
27
438
438
438
438
1.474e+38
0.3
1.848e+38
0.3
3.321e+38
0.6
28
438
475
475
484
1.474e+38
0.3
1.284e+38
0.2
2.757e+38
0.5
29
608
608
608
608
30
626
626
626
627
1.125e+38
0.2
2.867e+37
0.1
1.412e+38
0.3
31
656
656
656
656
1.232e+37
0.0
1.826e+37
0.0
3.058e+37
0.1
32
656
657
657
656
1.232e+37
0.0
1.562e+37
0.0
2.794e+37
0.1
33
657
657
657
657
8.901e+37
0.2
7.806e+37
0.1
1.671e+38
0.3
34
657
676
676
657
8.902e+37
0.2
1.111e+38
0.2
2.001e+38
0.4
35
929
929
929
943
5.323e+39
9.6
9.995e+37
0.2
5.423e+39
9.8
36
943
943
943
943
9.725e+38
1.8
1.039e+39
1.9
2.012e+39
3.6
37
943
943
943
944
9.725e+38
1.8
1.027e+39
1.9
2.000e+39
3.6
38
944
944
944
944
2.113e+38
0.4
2.906e+38
0.5
5.020e+38
0.9
39
944
980
980
958
2.113e+38
0.4
2.906e+38
0.5
5.020e+38
0.9
40
980
1017
1017
980
41
1017
1057
1057
1100
3.247e+39
5.9
6.362e+37
0.1
3.311e+39
6.0
42
1100
1100
1100
1110
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.