-    DOLOMITE-Sr     -    SrCa(CO3)2

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:  148  R-3 
Lattice parameters (Å):  4.8064  4.8064  16.0060 
Angles (°):  90  90  120 

Symmetry (theoretical): 

Space group:  148  R-3 
Lattice parameters (Å):  5.5210  5.5210  5.5210 
Angles (°):  55.56  55.56  55.56 

Cell contents: 

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

Atomic positions (theoretical):

Ca:  0.0000  0.0000  0.0000 
Sr:  0.5000  0.5000  0.5000 
C:  0.2521  0.2521  0.2521 
O:  0.5058  0.0154  0.2339 
O:  0.0154  0.2339  0.5058 
O:  0.2339  0.5058  0.0154 
C:  0.7479  0.7479  0.7479 
O:  0.4942  0.9846  0.7661 
O:  0.9846  0.7661  0.4942 
O:  0.7661  0.4942  0.9846 
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.

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
Au
-144
-144
-144
-80
2
Eu
-49
-49
-49
-49
3
Eu
-49
0
0
-49
4
Ac
0
0
0
0
5
Ac
0
0
0
0
6
Ac
0
42
42
0
7
Au
233
233
233
233
8
Ag
239
239
239
239
8.243e+37
0.1
3.761e+37
0.0
1.200e+38
0.1
9
Eg
244
244
244
244
5.193e+39
5.9
8.242e+39
9.4
1.343e+40
15.3
10
Eg
244
244
244
244
5.193e+39
5.9
6.947e+39
7.9
1.214e+40
13.9
11
Eu
245
245
245
245
12
Eu
245
263
263
245
13
Eg
364
364
364
364
1.202e+40
13.7
9.866e+39
11.3
2.188e+40
25.0
14
Eg
364
364
364
364
1.202e+40
13.7
1.721e+40
19.7
2.923e+40
33.4
15
Ag
395
395
395
395
4.035e+38
0.5
2.200e+38
0.3
6.235e+38
0.7
16
Au
406
406
406
421
17
Eu
421
421
421
421
18
Eu
421
477
477
466
19
Eg
729
729
729
729
5.485e+39
6.3
6.808e+39
7.8
1.229e+40
14.0
20
Eg
729
729
729
729
5.485e+39
6.3
4.246e+39
4.8
9.732e+39
11.1
21
Eu
738
738
738
738
22
Eu
738
742
742
738
23
Au
832
832
832
834
24
Ag
834
834
834
850
2.125e+39
2.4
5.927e+36
0.0
2.131e+39
2.4
25
Au
1159
1159
1159
1159
26
Ag
1160
1160
1160
1160
8.465e+40
96.7
2.927e+39
3.3
8.757e+40
100.0
27
Eu
1486
1486
1486
1486
28
Eu
1486
1534
1534
1486
29
Eg
1534
1534
1534
1534
2.054e+39
2.3
2.040e+39
2.3
4.094e+39
4.7
30
Eg
1534
1637
1637
1534
2.054e+39
2.3
2.310e+39
2.6
4.364e+39
5.0
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.