-    PARATELLURITE     -    TeO2

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:  92  P4_12_12 
Lattice parameters (Å):  4.8050  4.8050  7.6090 
Angles (°):  90.0  90.0  90.0 

Symmetry (theoretical): 

Space group:  92  P4_12_12 
Lattice parameters (Å):  4.6879  4.6879  7.3496 
Angles (°):  90.0  90.0  90.0 

Cell contents: 

Number of atoms:  12 
Number of atom types:  2 
Chemical composition:  0 

Atomic positions (theoretical):

Te:  0.0199  0.0199  0.0000 
O:  0.1417  0.2522  0.1884 
Te:  0.4801  0.5199  0.2500 
O:  0.2478  0.6417  0.4384 
O:  0.3583  0.7522  0.0616 
Te:  0.9801  0.9801  0.5000 
O:  0.8583  0.7478  0.6884 
O:  0.7478  0.8583  0.3116 
O:  0.2522  0.1417  0.8116 
Te:  0.5199  0.4801  0.7500 
O:  0.7522  0.3583  0.9384 
O:  0.6417  0.2478  0.5616 
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
B1
66
66
66
66
8.409e+40
3.2
6.307e+40
2.4
1.472e+41
5.7
5
A2
94
94
94
116
6
E
129
129
129
129
2.701e+41
10.4
3.714e+41
14.3
6.415e+41
24.8
7
E
129
130
130
129
2.701e+41
10.4
3.714e+41
14.3
6.415e+41
24.8
8
B1
140
140
140
140
6.385e+39
0.2
4.789e+39
0.2
1.117e+40
0.4
9
A1
152
152
152
152
1.276e+42
49.3
4.876e+39
0.2
1.281e+42
49.5
10
B2
155
155
155
155
1.359e+41
5.2
1.868e+41
7.2
3.227e+41
12.5
11
B1
181
181
181
181
2.322e+40
0.9
1.742e+40
0.7
4.064e+40
1.6
12
E
183
183
183
183
5.651e+40
2.2
7.770e+40
3.0
1.342e+41
5.2
13
E
183
205
205
183
5.651e+40
2.2
7.770e+40
3.0
1.342e+41
5.2
14
B1
213
213
213
213
3.363e+40
1.3
2.522e+40
1.0
5.886e+40
2.3
15
E
216
216
216
216
2.511e+39
0.1
3.452e+39
0.1
5.963e+39
0.2
16
E
216
245
245
216
2.511e+39
0.1
3.452e+39
0.1
5.963e+39
0.2
17
A1
245
246
246
245
6.130e+40
2.4
1.415e+39
0.1
6.271e+40
2.4
18
A2
268
268
268
270
19
B2
295
295
295
295
2.205e+40
0.9
3.031e+40
1.2
5.236e+40
2.0
20
E
300
300
300
300
5.856e+39
0.2
8.052e+39
0.3
1.391e+40
0.5
21
E
300
322
322
300
5.856e+39
0.2
8.052e+39
0.3
1.391e+40
0.5
22
A2
322
332
332
335
23
E
335
335
335
335
2.942e+40
1.1
4.045e+40
1.6
6.987e+40
2.7
24
E
335
353
353
353
2.942e+40
1.1
4.045e+40
1.6
6.987e+40
2.7
25
E
353
353
353
353
9.047e+39
0.3
1.244e+40
0.5
2.149e+40
0.8
26
E
353
394
394
392
9.047e+39
0.3
1.244e+40
0.5
2.149e+40
0.8
27
A1
394
421
421
394
6.338e+41
24.5
2.910e+40
1.1
6.629e+41
25.6
28
B2
421
421
421
421
1.111e+39
0.0
1.527e+39
0.1
2.638e+39
0.1
29
B1
571
571
571
571
7.575e+40
2.9
5.681e+40
2.2
1.326e+41
5.1
30
A2
573
573
573
630
31
E
630
630
630
630
1.569e+40
0.6
2.158e+40
0.8
3.727e+40
1.4
32
E
630
634
634
634
1.569e+40
0.6
2.158e+40
0.8
3.727e+40
1.4
33
A1
634
702
702
750
2.587e+42
99.9
2.778e+39
0.1
2.589e+42
100.0
34
E
750
750
750
750
4.161e+40
1.6
5.722e+40
2.2
9.883e+40
3.8
35
E
750
762
762
753
4.161e+40
1.6
5.722e+40
2.2
9.883e+40
3.8
36
B2
762
796
796
762
5.406e+40
2.1
7.434e+40
2.9
1.284e+41
5.0
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.