-    SODIUM SULFATE     -    Na2SO4

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 ICSD database; code 76002 

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:  63  Cmcm 
Lattice parameters (Å):  5.6000  8.9500  6.9900 
Angles (°):  90.0  90.0  90.0 

Symmetry (theoretical): 

Space group:  63  Cmcm 
Lattice parameters (Å):  5.1210  5.1210  6.7593 
Angles (°):  90  90  64.50 

Cell contents: 

Number of atoms:  14 
Number of atom types:  3 
Chemical composition:  0 

Atomic positions (theoretical):

Na:  0.1887  0.1887  0.2500 
Na:  0.5000  0.5000  0.0000 
S:  0.8504  0.8504  0.2500 
O:  0.7309  0.1707  0.2500 
O:  0.2473  0.2473  0.5732 
Na:  0.8113  0.8113  0.7500 
Na:  0.5000  0.5000  0.5000 
S:  0.1496  0.1496  0.7500 
O:  0.2691  0.8293  0.7500 
O:  0.7527  0.7527  0.0732 
O:  0.1707  0.7309  0.2500 
O:  0.2473  0.2473  0.9268 
O:  0.8293  0.2691  0.7500 
O:  0.7527  0.7527  0.4268 
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
B3u
17
61
17
17
5
B3g
61
70
61
61
3.897e+37
0.0
5.359e+37
0.0
9.256e+37
0.1
6
B1g
70
79
70
70
1.554e+38
0.1
2.137e+38
0.2
3.691e+38
0.3
7
Au
102
102
102
102
8
B1u
125
125
125
125
9
B3u
132
137
132
132
10
Ag
137
140
137
137
3.830e+38
0.3
2.785e+38
0.2
6.615e+38
0.5
11
B1g
140
148
140
140
5.630e+38
0.4
7.742e+38
0.6
1.337e+39
1.0
12
B1g
165
165
165
165
2.033e+38
0.1
2.796e+38
0.2
4.829e+38
0.4
13
B2g
181
181
181
181
4.476e+38
0.3
6.154e+38
0.5
1.063e+39
0.8
14
Au
190
190
190
190
15
Ag
190
190
190
190
3.195e+38
0.2
2.294e+38
0.2
5.489e+38
0.4
16
B2u
193
193
194
193
17
B3g
194
194
213
194
1.612e+36
0.0
2.216e+36
0.0
3.828e+36
0.0
18
B3u
213
223
219
213
19
B1u
223
248
223
228
20
B2u
248
254
248
248
21
B1u
254
268
254
268
22
B2u
268
276
276
270
23
B1u
276
280
286
286
24
B3g
286
286
312
308
1.124e+38
0.1
1.545e+38
0.1
2.669e+38
0.2
25
Au
437
437
437
437
26
B2g
448
448
448
448
6.828e+39
5.0
9.388e+39
6.9
1.622e+40
12.0
27
Ag
460
460
460
460
4.862e+39
3.6
3.531e+39
2.6
8.393e+39
6.2
28
B2u
472
472
472
472
29
B3u
588
592
588
588
30
B1g
592
598
592
592
6.282e+39
4.6
8.638e+39
6.4
1.492e+40
11.0
31
B1u
606
606
606
618
32
B2u
618
618
623
623
33
Ag
623
623
624
624
4.363e+39
3.2
3.227e+39
2.4
7.589e+39
5.6
34
B3g
624
624
634
626
3.769e+39
2.8
5.182e+39
3.8
8.950e+39
6.6
35
B2u
986
986
987
986
36
Ag
987
987
989
987
1.353e+41
99.8
3.230e+38
0.2
1.356e+41
100.0
37
B1g
1071
1071
1071
1071
5.406e+39
4.0
7.433e+39
5.5
1.284e+40
9.5
38
B3u
1091
1135
1091
1091
39
Ag
1135
1142
1135
1135
9.518e+39
7.0
3.440e+39
2.5
1.296e+40
9.6
40
B1u
1142
1142
1142
1142
41
B2u
1142
1177
1208
1208
42
B3g
1208
1208
1222
1230
6.469e+39
4.8
8.894e+39
6.6
1.536e+40
11.3
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.