-    ERNIGGLIITE     -    SnTl2As2S6

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:  147  P-3 
Lattice parameters (Å):  6.6800  6.6800  7.1640 
Angles (°):  90  90  120 

Symmetry (theoretical): 

Space group:  147  P-3 
Lattice parameters (Å):  6.4641  6.4641  6.5197 
Angles (°):  90  90  120 

Cell contents: 

Number of atoms:  11 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Sn:  0.0000  0.0000  0.0000 
Tl:  0.3333  0.6667  0.4074 
As:  0.3333  0.6667  0.9360 
0.2430  0.3336  0.7539 
0.0906  0.7570  0.7539 
0.6664  0.9094  0.7539 
Tl:  0.6667  0.3333  0.5926 
As:  0.6667  0.3333  0.0640 
0.7570  0.6664  0.2461 
0.9094  0.2430  0.2461 
0.3336  0.0906  0.2461 
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
Ag
40
40
40
40
2.137e+42
2.1
1.883e+39
0.0
2.138e+42
2.1
5
Eg
41
41
41
41
3.126e+41
0.3
4.966e+41
0.5
8.092e+41
0.8
6
Eg
41
41
41
41
3.126e+41
0.3
2.632e+41
0.3
5.758e+41
0.6
7
Eu
52
52
52
52
8
Eu
52
54
54
52
9
Eg
74
74
74
74
1.500e+42
1.5
2.179e+42
2.2
3.679e+42
3.7
10
Eg
74
74
74
74
1.500e+42
1.5
1.206e+42
1.2
2.706e+42
2.7
11
Au
77
77
77
89
12
Ag
98
98
98
98
2.965e+41
0.3
4.412e+40
0.0
3.406e+41
0.3
13
Au
111
111
111
111
14
Eu
111
111
111
111
15
Eu
111
117
117
111
16
Ag
132
132
132
132
2.815e+43
28.1
1.492e+41
0.1
2.830e+43
28.3
17
Au
142
142
142
145
18
Eu
145
145
145
145
19
Eu
145
150
150
146
20
Eg
150
150
150
150
2.778e+42
2.8
3.711e+42
3.7
6.489e+42
6.5
21
Eg
150
164
164
150
2.778e+42
2.8
2.292e+42
2.3
5.070e+42
5.1
22
Eg
242
242
242
242
7.569e+41
0.8
8.023e+41
0.8
1.559e+42
1.6
23
Eg
242
242
242
242
7.569e+41
0.8
7.962e+41
0.8
1.553e+42
1.6
24
Eu
270
270
270
270
25
Eu
270
286
286
270
26
Ag
296
296
296
296
9.742e+43
97.4
2.649e+42
2.6
1.001e+44
100.0
27
Au
313
313
313
318
28
Eg
318
318
318
318
8.318e+41
0.8
1.102e+42
1.1
1.933e+42
1.9
29
Eg
318
318
318
320
8.318e+41
0.8
8.528e+41
0.9
1.685e+42
1.7
30
Eu
320
320
320
320
31
Eu
320
338
338
334
32
Ag
372
372
372
372
5.679e+42
5.7
6.513e+40
0.1
5.745e+42
5.7
33
Au
376
376
376
385
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.