-    PYRITE     -    FeS2

 

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:  205  Pa-3 
Lattice parameters (Å):  5.4160  5.4160  5.4160 
Angles (°):  90  90  90 

Symmetry (theoretical): 

Space group:  205  Pa-3 
Lattice parameters (Å):  5.3236  5.3236  5.3236 
Angles (°):  90  90  90 

Cell contents: 

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

Atomic positions (theoretical):

Fe:  0.0000  0.0000  0.0000 
S:  0.3825  0.3825  0.3825 
Fe:  0.5000  0.0000  0.5000 
S:  0.1175  0.6175  0.8825 
Fe:  0.0000  0.5000  0.5000 
S:  0.6175  0.8825  0.1175 
Fe:  0.5000  0.5000  0.0000 
S:  0.8825  0.1175  0.6175 
S:  0.6175  0.6175  0.6175 
S:  0.8825  0.3825  0.1175 
S:  0.3825  0.1175  0.8825 
S:  0.1175  0.8825  0.3825 
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
Ac
0
0
0
0
2
Ac
0
0
0
0
3
Ac
0
205
205
205
4
Tu
205
205
205
205
5
Tu
205
205
205
205
6
Tu
205
224
224
224
7
Au
224
239
239
239
8
Ag
239
239
239
239
2.452e+38
100.0
0.000e+0
0.0
2.452e+38
100.0
9
Au
239
312
312
312
10
Tu
312
312
312
312
11
Tu
312
312
312
312
12
Tu
312
347
347
347
13
Au
347
351
351
351
14
Ag
351
351
351
351
1.635e+38
66.7
0.000e+0
0.0
1.635e+38
66.7
15
Ag
351
357
357
357
1.635e+38
66.7
0.000e+0
0.0
1.635e+38
66.7
16
Tu
357
357
357
357
17
Tu
357
357
357
357
18
Tu
357
362
362
362
19
Tg
362
362
362
362
1.582e+38
64.5
0.000e+0
0.0
1.582e+38
64.5
20
Tg
362
362
362
362
1.582e+38
64.5
0.000e+0
0.0
1.582e+38
64.5
21
Tg
362
381
381
381
1.582e+38
64.5
0.000e+0
0.0
1.582e+38
64.5
22
Ag
381
384
384
384
1.498e+38
61.1
0.000e+0
0.0
1.498e+38
61.1
23
Tu
384
384
384
384
24
Tu
384
384
384
384
25
Tu
384
393
393
393
26
Ag
393
393
393
393
1.449e+38
59.1
0.000e+0
0.0
1.449e+38
59.1
27
Au
393
400
400
400
28
Tg
400
400
400
400
1.422e+38
58.0
0.000e+0
0.0
1.422e+38
58.0
29
Tg
400
400
400
400
1.422e+38
58.0
0.000e+0
0.0
1.422e+38
58.0
30
Tg
400
408
408
408
1.422e+38
58.0
0.000e+0
0.0
1.422e+38
58.0
31
Tu
414
414
414
414
32
Tu
414
414
414
414
33
Tu
414
424
424
424
34
Tg
424
424
424
424
1.335e+38
54.5
0.000e+0
0.0
1.335e+38
54.5
35
Tg
424
424
424
424
1.335e+38
54.5
0.000e+0
0.0
1.335e+38
54.5
36
Tg
424
1096
1102
1103
1.335e+38
54.5
0.000e+0
0.0
1.335e+38
54.5
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.