-    HYDROPHILITE     -    CaCl2

Experimental structure. Atomic positions and lattice parameters 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:  58  Pnnm 
Lattice parameters (Å):  0.0000  0.0000  0.0000 
Angles (°):  90.0  90.0  90.0 

Symmetry (theoretical): 

Space group:  58  Pnnm 
Lattice parameters (Å):  6.2400  6.4300  4.2000 
Angles (°):  90.0  90.0  90.0 

Cell contents: 

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

Atomic positions (theoretical):

Ca:  0.0000  0.0000  0.0000 
Cl:  0.2750  0.3250  0.0000 
Cl:  0.7250  0.6750  0.0000 
Ca:  0.5000  0.5000  0.5000 
Cl:  0.2250  0.8250  0.5000 
Cl:  0.7750  0.1750  0.5000 
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
ac
0
0
0
0
2
ac
0
0
0
0
3
ac
0
0
0
0
4
A1g
38
38
38
38
6.107e+39
95.0
3.204e+38
5.0
6.427e+39
100.0
5
Au
67
67
67
67
6
B2u
71
71
86
71
7
B3u
86
95
89
86
8
B1g
95
105
95
95
5.659e+38
8.8
7.781e+38
12.1
1.344e+39
20.9
9
B3g
146
146
146
146
6.257e+38
9.7
8.603e+38
13.4
1.486e+39
23.1
10
B2g
147
147
147
147
9.997e+38
15.6
1.375e+39
21.4
2.374e+39
36.9
11
A1g
209
209
209
209
4.215e+39
65.6
9.671e+38
15.0
5.182e+39
80.6
12
B1u
212
212
212
219
13
Au
219
219
219
219
14
B3u
219
221
219
224
15
B2u
224
224
225
249
16
B1g
249
249
249
252
4.896e+38
7.6
6.732e+38
10.5
1.163e+39
18.1
17
B2u
252
252
255
255
18
B3u
255
321
324
304
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.