-    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):  4.2468  10.5425  3.8268 
Angles (°):  90  90  90 

Cell contents: 

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

Atomic positions (theoretical):

Sn:  0.1448  0.1113  0.2500 
S:  0.4513  0.8556  0.2500 
Sn:  0.6448  0.3887  0.7500 
S:  0.9513  0.6444  0.7500 
Sn:  0.8552  0.8887  0.7500 
S:  0.5487  0.1444  0.7500 
Sn:  0.3552  0.6113  0.2500 
S:  0.0487  0.3556  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
49
49
49
49
1.272e+42
2.6
7.602e+41
1.5
2.032e+42
4.1
5
B2g
54
54
54
54
5.340e+41
1.1
7.343e+41
1.5
1.268e+42
2.6
6
Au
60
60
60
60
7
B2u
70
70
72
70
8
B3g
79
79
79
79
2.042e+42
4.1
2.807e+42
5.6
4.849e+42
9.8
9
B1g
91
91
91
91
10
A1g
96
96
96
96
2.349e+42
4.7
1.721e+42
3.5
4.069e+42
8.2
11
B1g
100
100
100
100
1.716e+41
0.3
2.359e+41
0.5
4.075e+41
0.8
12
B3u
118
123
118
118
13
B2u
173
173
175
173
14
B1u
175
175
194
194
15
B2g
194
194
207
207
2.093e+43
42.1
2.877e+43
57.9
4.970e+43
100.0
16
B3u
207
216
216
216
17
Au
216
217
217
217
18
A1g
217
223
223
223
4.678e+43
94.1
2.184e+42
4.4
4.896e+43
98.5
19
B3g
223
235
235
236
1.029e+40
0.0
1.414e+40
0.0
2.443e+40
0.0
20
B2u
236
236
244
244
21
A1g
244
244
245
245
3.837e+41
0.8
1.806e+41
0.4
5.642e+41
1.1
22
B3u
245
262
262
262
23
B1g
262
283
283
272
9.206e+41
1.9
1.266e+42
2.5
2.186e+42
4.4
24
B1g
283
301
360
283
3.876e+41
0.8
5.330e+41
1.1
9.206e+41
1.9
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.