-    OTAVITE     -    CdCO3

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:  167  R-3c 
Lattice parameters (Å):  4.9207  4.9207  16.2968 
Angles (°):  90  90  120 

Symmetry (theoretical): 

Space group:  167  R-3c 
Lattice parameters (Å):  6.0849  6.0849  6.0849 
Angles (°):  47.97  47.97  47.97 

Cell contents: 

Number of atoms:  10 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Cd:  0.0000  0.0000  0.0000 
H:  0.2500  0.2500  0.2500 
O:  0.5084  0.9916  0.2500 
O:  0.9916  0.2500  0.5084 
Cd:  0.5000  0.5000  0.5000 
H:  0.7500  0.7500  0.7500 
O:  0.7500  0.4916  0.0084 
O:  0.2500  0.5084  0.9916 
O:  0.4916  0.0084  0.7500 
O:  0.0084  0.7500  0.4916 
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
A2u
85
85
85
110
5
Eu
110
110
110
110
6
Eu
110
116
116
150
7
Eu
154
154
154
154
8
Eu
154
159
159
154
9
Eg
159
159
159
159
1.036e+40
9.1
1.281e+40
11.3
2.318e+40
20.4
10
Eg
159
166
166
159
1.036e+40
9.1
1.633e+40
14.4
2.669e+40
23.5
11
A1u
166
183
183
166
12
A2g
188
188
188
188
13
Eg
263
263
263
263
4.579e+40
40.3
6.777e+40
59.7
1.136e+41
100.0
14
Eg
263
263
263
263
4.579e+40
40.3
3.833e+40
33.8
8.413e+40
74.1
15
Eu
281
281
281
281
16
Eu
281
315
315
281
17
A2u
315
329
329
360
18
A2g
371
371
371
371
19
Eg
702
702
702
702
2.570e+38
0.2
3.181e+38
0.3
5.751e+38
0.5
20
Eu
702
702
702
702
2.570e+38
0.2
4.175e+38
0.4
6.744e+38
0.6
21
Eu
709
709
709
709
22
A2u
709
710
710
709
23
A2g
831
831
831
837
24
A1u
837
837
837
840
25
A1g
1087
1087
1087
1087
26
Eu
1089
1089
1089
1089
8.684e+40
76.5
1.916e+39
1.7
8.876e+40
78.2
27
Eu
1387
1387
1387
1387
28
Eg
1387
1390
1390
1387
29
Eg
1390
1390
1390
1390
3.843e+40
33.8
4.837e+40
42.6
8.680e+40
76.4
30
A2u
1390
1530
1530
1390
3.843e+40
33.8
4.992e+40
44.0
8.836e+40
77.8
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.