-    Magnesium Sulfate-alpha     -    MgSO4

 

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):  5.1686  7.8678  6.4667 
Angles (°):  90  90  90 

Symmetry (theoretical): 

Space group:  63  Cmcm 
Lattice parameters (Å):  4.6543  4.6543  6.3135 
Angles (°):  90  90  66.57 

Cell contents: 

Number of atoms:  12 
Number of atom types:  3 
Chemical composition:  0 

Atomic positions (theoretical):

Mg:  0.0000  0.0000  0.0000 
S:  0.3519  0.3519  0.2500 
O:  0.2495  0.2495  0.0585 
O:  0.7011  0.2277  0.2500 
Mg:  0.0000  0.0000  0.5000 
S:  0.6481  0.6481  0.7500 
O:  0.7505  0.7505  0.5585 
O:  0.2989  0.7723  0.7500 
O:  0.2495  0.2495  0.4415 
O:  0.2277  0.7011  0.2500 
O:  0.7505  0.7505  0.9415 
O:  0.7723  0.2989  0.7500 
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
B3g
155
155
155
155
6.833e+37
0.1
9.395e+37
0.1
1.623e+38
0.1
5
B3u
158
167
158
158
6
B1u
180
180
180
184
7
B1g
184
184
184
190
7.445e+38
0.6
1.024e+39
0.8
1.768e+39
1.4
8
Au
195
195
195
195
9
A1g
212
212
212
212
8.233e+39
6.3
3.420e+38
0.3
8.575e+39
6.6
10
B1g
242
242
242
242
11
Au
248
248
248
248
12
B1u
271
271
271
288
13
B2g
288
288
288
291
8.660e+38
0.7
1.191e+39
0.9
2.057e+39
1.6
14
B3u
291
310
291
298
15
B3g
310
352
310
310
3.199e+37
0.0
4.399e+37
0.0
7.598e+37
0.1
16
B2u
352
410
388
352
17
B1u
410
425
410
429
18
B2u
429
429
443
453
19
A1g
456
456
456
456
9.527e+39
7.3
5.715e+39
4.4
1.524e+40
11.7
20
Au
481
481
481
481
21
B2g
492
492
492
492
9.894e+39
7.6
1.360e+40
10.4
2.350e+40
18.0
22
B2u
493
493
525
493
23
B3u
595
598
595
595
24
B1g
598
599
598
598
9.424e+39
7.2
1.296e+40
10.0
2.238e+40
17.2
25
B2u
599
599
601
599
26
A1g
601
601
621
601
1.878e+40
14.4
6.359e+39
4.9
2.514e+40
19.3
27
B1u
669
669
669
682
28
B3g
682
682
682
701
5.042e+39
3.9
6.932e+39
5.3
1.197e+40
9.2
29
Ag
998
998
998
998
1.280e+41
98.3
2.153e+39
1.7
1.302e+41
100.0
30
Ag
998
998
1008
998
1.331e+40
10.2
2.239e+38
0.2
1.354e+40
10.4
31
B1g
1012
1012
1012
1012
7.657e+39
5.9
1.053e+40
8.1
1.819e+40
14.0
32
B3u
1038
1146
1038
1038
33
A1g
1146
1160
1146
1146
3.637e+40
27.9
3.569e+39
2.7
3.993e+40
30.7
34
B2u
1160
1174
1207
1160
35
B1u
1207
1207
1264
1276
36
B3g
1276
1276
1276
1303
6.602e+39
5.1
9.077e+39
7.0
1.568e+40
12.0
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.