-    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):  3.9319  10.1732  3.7361 
Angles (°):  90  90  90 

Cell contents: 

Number of atoms:  8 
Number of atom types:  2 
Chemical composition:  0 

Atomic positions (theoretical):

Sn:  0.0956  0.1128  0.2500 
S:  0.4616  0.8595  0.2500 
Sn:  0.5956  0.3872  0.7500 
S:  0.9616  0.6405  0.7500 
Sn:  0.9044  0.8872  0.7500 
S:  0.5384  0.1405  0.7500 
Sn:  0.4044  0.6128  0.2500 
S:  0.0384  0.3595  0.2500 
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
A1g
41
41
41
41
2.842e+43
18.1
6.065e+42
3.9
3.448e+43
22.0
5
Au
58
58
58
58
6
B2u
67
67
67
67
7
B2g
72
72
72
72
6.938e+41
0.4
9.540e+41
0.6
1.648e+42
1.1
8
B1g
82
82
82
82
1.396e+41
0.1
1.919e+41
0.1
3.315e+41
0.2
9
B3g
94
94
94
94
3.995e+42
2.5
5.492e+42
3.5
9.487e+42
6.1
10
A1g
128
128
128
128
1.945e+43
12.4
1.353e+43
8.6
3.298e+43
21.0
11
B1g
129
129
129
129
12
B3u
130
131
130
130
13
B1u
165
165
165
208
14
B2u
208
208
209
209
15
B3u
209
210
210
210
16
B2g
210
234
234
234
5.891e+43
37.6
8.101e+43
51.7
1.399e+44
89.3
17
A1g
234
236
236
236
1.439e+44
91.8
1.279e+43
8.2
1.567e+44
100.0
18
Au
236
248
248
248
19
B3g
248
251
251
251
2.866e+40
0.0
3.941e+40
0.0
6.807e+40
0.0
20
B2u
251
278
283
283
21
B3u
283
288
288
288
22
B1g
288
299
299
297
1.820e+42
1.2
2.502e+42
1.6
4.322e+42
2.8
23
A1g
299
311
311
299
3.882e+43
24.8
3.224e+42
2.1
4.205e+43
26.8
24
B1g
311
320
384
311
1.070e+42
0.7
1.471e+42
0.9
2.541e+42
1.6
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.