-    DOLOMITE-Sr     -    SrCa(CO3)2

The crystal structure is fully relaxed (both unit cell parameters and atomic positions under symmetry constraints) starting from an experimental structure of dolomite, 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:  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):  6.4265  6.4265  6.4265 
Angles (°):  46.59  46.59  46.59 

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:  0.5140  0.0132  0.2277 
O:  0.0132  0.2277  0.5140 
O:  0.2277  0.5140  0.0132 
C:  0.7479  0.7479  0.7479 
O:  0.4860  0.9868  0.7723 
O:  0.9868  0.7723  0.4860 
O:  0.7723  0.4860  0.9868 
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
0
0
0
0
2
0
0
0
0
3
0
0
0
0
4
29
29
29
73
5
73
73
73
73
6
73
99
99
107
7
138
138
138
138
5.923e+38
1.8
2.750e+33
0.0
5.923e+38
1.8
8
153
153
153
153
6.151e+39
19.0
9.098e+39
28.0
1.525e+40
47.0
9
153
153
153
153
6.151e+39
19.0
8.750e+39
27.0
1.490e+40
45.9
10
220
220
220
220
11
220
237
237
220
12
256
256
256
256
13
308
308
308
308
1.014e+40
31.2
1.383e+40
42.6
2.397e+40
73.9
14
308
308
308
308
1.014e+40
31.2
1.204e+40
37.1
2.218e+40
68.4
15
337
337
337
337
2.031e+38
0.6
1.811e+37
0.1
2.212e+38
0.7
16
342
342
342
342
17
342
363
363
342
18
363
397
397
422
19
708
708
708
708
1.910e+39
5.9
1.638e+39
5.0
3.549e+39
10.9
20
708
708
708
708
1.910e+39
5.9
2.203e+39
6.8
4.114e+39
12.7
21
712
712
712
712
22
712
713
713
712
23
850
850
850
855
24
855
855
855
864
1.691e+38
0.5
2.552e+35
0.0
1.693e+38
0.5
25
1100
1100
1100
1101
3.143e+40
96.9
1.014e+39
3.1
3.245e+40
100.0
26
1101
1101
1101
1101
3.085e+40
95.1
9.958e+38
3.1
3.185e+40
98.2
27
1426
1426
1426
1426
28
1426
1453
1453
1426
29
1453
1453
1453
1453
2.197e+39
6.8
2.987e+39
9.2
5.184e+39
16.0
30
1453
1562
1562
1453
2.197e+39
6.8
1.788e+39
5.5
3.984e+39
12.3
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.