-    THENARDITE     -    Na2SO4

Theoretical atomic positions and lattice parameters at experimental volum from 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:  70  Fddd 
Lattice parameters (Å):  9.8290  12.3020  5.8680 
Angles (°):  90  90  90 

Symmetry (theoretical): 

Space group:  70  Fddd 
Lattice parameters (Å):  6.6339  5.5348  7.6337 
Angles (°):  57.90  44.97  77.12 

Cell contents: 

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

Atomic positions (theoretical):

Na:  0.8098  0.4402  0.4402 
S:  0.1250  0.1250  0.1250 
O:  0.8146  0.1379  0.2965 
Na:  0.4402  0.8098  0.8098 
O:  0.1379  0.8146  0.2510 
O:  0.2965  0.2510  0.8146 
O:  0.2510  0.2965  0.1379 
Na:  0.1902  0.5598  0.5598 
S:  0.8750  0.8750  0.8750 
O:  0.1854  0.8621  0.7035 
Na:  0.5598  0.1902  0.1902 
O:  0.8621  0.1854  0.7490 
O:  0.7035  0.7490  0.1854 
O:  0.7490  0.7035  0.8621 
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.

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
0
0
0
0
2
0
0
0
0
3
0
0
0
0
4
88
88
88
88
1.011e+38
0.1
1.391e+38
0.1
2.402e+38
0.2
5
90
90
90
90
5.778e+38
0.4
7.945e+38
0.5
1.372e+39
0.9
6
102
102
102
102
7
103
103
103
103
2.194e+37
0.0
3.017e+37
0.0
5.210e+37
0.0
8
143
143
143
143
8.588e+38
0.6
1.181e+39
0.8
2.040e+39
1.4
9
145
145
145
145
3.554e+37
0.0
4.887e+37
0.0
8.440e+37
0.1
10
147
147
147
147
1.678e+38
0.1
2.307e+38
0.2
3.985e+38
0.3
11
151
166
151
151
12
178
178
180
178
13
180
180
180
180
1.225e+39
0.8
2.838e+38
0.2
1.508e+39
1.0
14
188
188
188
188
15
197
197
197
199
16
199
199
199
200
2.416e+37
0.0
3.323e+37
0.0
5.739e+37
0.0
17
200
207
200
207
18
207
219
207
219
7.287e+37
0.1
1.002e+38
0.1
1.731e+38
0.1
19
219
226
221
226
20
226
257
226
243
1.884e+38
0.1
2.591e+38
0.2
4.476e+38
0.3
21
257
272
257
277
22
277
277
277
286
6.543e+37
0.0
8.996e+37
0.1
1.554e+38
0.1
23
286
286
287
287
24
287
287
329
290
1.375e+38
0.1
1.890e+38
0.1
3.265e+38
0.2
25
435
435
435
435
5.521e+39
3.8
4.110e+39
2.8
9.631e+39
6.6
26
445
445
445
445
27
461
461
461
461
5.538e+39
3.8
3.558e+39
2.4
9.096e+39
6.3
28
487
487
487
487
29
591
591
597
591
30
597
597
601
601
31
601
601
609
608
3.813e+39
2.6
5.242e+39
3.6
9.055e+39
6.2
32
614
614
614
614
5.000e+39
3.4
6.874e+39
4.7
1.187e+40
8.2
33
623
637
623
623
34
637
639
637
637
3.990e+39
2.7
5.486e+39
3.8
9.477e+39
6.5
35
978
978
978
978
36
982
982
982
982
1.454e+41
99.9
7.643e+37
0.1
1.454e+41
100.0
37
1098
1098
1098
1098
7.409e+39
5.1
1.019e+40
7.0
1.760e+40
12.1
38
1098
1098
1120
1098
39
1120
1128
1128
1120
40
1128
1135
1135
1135
41
1135
1157
1157
1157
4.987e+39
3.4
6.858e+39
4.7
1.184e+40
8.1
42
1157
1205
1186
1204
7.445e+39
5.1
1.024e+40
7.0
1.768e+40
12.2
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.