-    PROUSTITE     -    Ag3AsS3

Theoretical atomic positions and lattice parameters at experimental volum from 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:  161  R3c 
Lattice parameters (Å):  10.7680  10.7680  8.7200 
Angles (°):  90  90  120 

Symmetry (theoretical): 

Space group:  161  R3c 
Lattice parameters (Å):  6.8094  6.8094  6.8094 
Angles (°):  101.91  101.91  101.91 

Cell contents: 

Number of atoms:  14 
Number of atom types:  3 
Chemical composition:  0 

Atomic positions (theoretical):

Ag:  0.4677  0.2442  0.9188 
As:  0.0083  0.0083  0.0083 
S:  0.5994  0.2637  0.2843 
Ag:  0.2442  0.9188  0.4677 
S:  0.2637  0.2843  0.5994 
Ag:  0.4188  0.7442  0.9677 
As:  0.5083  0.5083  0.5083 
S:  0.7843  0.7637  0.0994 
Ag:  0.9188  0.4677  0.2442 
S:  0.2843  0.5994  0.2637 
Ag:  0.7442  0.9677  0.4188 
S:  0.7637  0.0994  0.7843 
Ag:  0.9677  0.4188  0.7442 
S:  0.0994  0.7843  0.7637 
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
-19
-19
-19
-19
2
-19
-16
-16
-19
3
-15
-15
-15
-15
4
0
0
0
0
5
0
0
0
0
6
0
0
0
0
7
31
31
31
31
2.157e+40
0.1
2.910e+40
0.2
5.066e+40
0.3
8
31
32
32
31
2.157e+40
0.1
2.090e+40
0.1
4.247e+40
0.2
9
36
36
36
36
2.211e+41
1.2
3.385e+41
1.9
5.596e+41
3.1
10
36
37
37
36
2.211e+41
1.2
2.867e+41
1.6
5.078e+41
2.8
11
39
39
39
41
7.405e+40
0.4
2.796e+39
0.0
7.685e+40
0.4
12
42
42
42
42
13
43
43
43
45
3.828e+42
21.0
2.626e+41
1.4
4.090e+42
22.5
14
45
45
45
45
2.069e+41
1.1
2.925e+41
1.6
4.994e+41
2.7
15
45
47
47
47
2.069e+41
1.1
3.000e+41
1.6
5.068e+41
2.8
16
57
57
57
57
17
65
65
65
65
2.039e+41
1.1
2.778e+41
1.5
4.817e+41
2.6
18
65
65
65
65
2.039e+41
1.1
3.075e+41
1.7
5.114e+41
2.8
19
107
107
107
107
5.433e+40
0.3
9.033e+40
0.5
1.447e+41
0.8
20
107
107
107
107
5.433e+40
0.3
5.342e+40
0.3
1.078e+41
0.6
21
125
125
125
125
1.244e+41
0.7
1.023e+41
0.6
2.267e+41
1.2
22
125
126
126
125
1.244e+41
0.7
1.465e+41
0.8
2.709e+41
1.5
23
145
145
145
145
9.505e+41
5.2
7.349e+40
0.4
1.024e+42
5.6
24
151
151
151
151
25
211
211
211
211
4.001e+42
22.0
3.076e+41
1.7
4.308e+42
23.7
26
239
239
239
239
4.680e+40
0.3
5.620e+40
0.3
1.030e+41
0.6
27
239
239
239
239
4.681e+40
0.3
3.729e+40
0.2
8.409e+40
0.5
28
240
240
240
240
9.330e+40
0.5
7.893e+40
0.4
1.722e+41
0.9
29
240
241
241
240
9.331e+40
0.5
1.443e+41
0.8
2.376e+41
1.3
30
252
252
252
252
31
267
267
267
267
6.209e+41
3.4
7.065e+41
3.9
1.327e+42
7.3
32
267
277
277
267
6.209e+41
3.4
5.394e+41
3.0
1.160e+42
6.4
33
280
280
280
280
2.457e+41
1.4
2.249e+40
0.1
2.682e+41
1.5
34
280
280
280
284
35
288
288
288
288
3.484e+40
0.2
4.960e+40
0.3
8.444e+40
0.5
36
288
288
288
288
3.484e+40
0.2
3.592e+40
0.2
7.077e+40
0.4
37
319
319
319
319
6.881e+41
3.8
1.106e+42
6.1
1.794e+42
9.9
38
319
326
326
319
6.881e+41
3.8
8.676e+41
4.8
1.556e+42
8.6
39
337
337
337
337
1.095e+41
0.6
1.316e+41
0.7
2.411e+41
1.3
40
337
342
342
337
1.095e+41
0.6
1.822e+41
1.0
2.918e+41
1.6
41
345
345
345
350
1.816e+43
99.8
2.927e+40
0.2
1.819e+43
100.0
42
355
355
355
355
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.