-    HERZENBERGITE     -    SnS

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:  62  Pbnm 
Lattice parameters (Å):  4.7104  10.2718  8.7476 
Angles (°):  90  90  90 

Symmetry (theoretical): 

Space group:  62  Pbnm 
Lattice parameters (Å):  3.8559  10.0326  3.6900 
Angles (°):  90  90  90 

Cell contents: 

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

Atomic positions (theoretical):

Sn:  0.0734  0.1139  0.2500 
S:  0.4695  0.8615  0.2500 
Sn:  0.5734  0.3861  0.7500 
S:  0.9695  0.6385  0.7500 
Sn:  0.9266  0.8861  0.7500 
S:  0.5305  0.1385  0.7500 
Sn:  0.4266  0.6139  0.2500 
S:  0.0305  0.3615  0.2500 
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.

Horizontal:
Xmin:
Xmax:
Vertical:
Ymin:
Ymax:
 
Choose the polarization of the lasers.
I ∥ 
I ⊥ 
I Total 

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
A1g
34
34
34
34
1.144e+44
36.6
2.212e+43
7.1
1.365e+44
43.7
5
Au
58
58
58
58
6
B2u
65
65
65
65
7
B1g
72
72
72
72
1.970e+41
0.1
2.708e+41
0.1
4.678e+41
0.1
8
B2g
79
79
79
79
9.769e+41
0.3
1.343e+42
0.4
2.320e+42
0.7
9
B3g
100
100
100
100
6.059e+42
1.9
8.332e+42
2.7
1.439e+43
4.6
10
B3u
131
131
131
131
11
A1g
140
140
140
140
1.597e+44
51.2
7.955e+43
25.5
2.393e+44
76.7
12
B1g
144
144
144
144
1.645e+39
0.0
2.262e+39
0.0
3.907e+39
0.0
13
B1u
159
159
159
210
14
B3u
210
218
210
218
15
B2g
218
223
218
223
7.159e+43
22.9
9.843e+43
31.5
1.700e+44
54.5
16
B2u
223
240
240
240
17
A1g
240
241
241
241
2.770e+44
88.8
3.511e+43
11.2
3.122e+44
100.0
18
Au
241
257
257
257
19
B3g
257
258
258
258
1.578e+40
0.0
2.169e+40
0.0
3.747e+40
0.0
20
B2u
258
295
298
298
21
B3u
298
299
299
299
22
B1g
299
323
323
306
2.464e+42
0.8
3.388e+42
1.1
5.851e+42
1.9
23
A1g
323
325
325
323
8.095e+43
25.9
8.617e+42
2.8
8.957e+43
28.7
24
B1g
325
328
391
325
1.040e+42
0.3
1.430e+42
0.5
2.470e+42
0.8
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.