-    PARALAURIONITE     -    PbClOH

The crystal structure is fully relaxed (both unit cell parameters and atomic positions under symmetry constraints) starting from an experimental structure 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:  12  C2/m 
Lattice parameters (Å):  10.8650  4.0060  7.2330 
Angles (°):  90.0  117.2  90.0 

Symmetry (theoretical): 

Space group:  12  C2/m 
Lattice parameters (Å):  5.6609  5.6609  7.0516 
Angles (°):  64.9  115.1  139.5 

Cell contents: 

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

Atomic positions (theoretical):

Pb:  0.1687  0.8313  0.2365 
Cl:  0.4308  0.5692  0.1904 
O:  0.2002  0.7998  0.5905 
H:  0.1188  0.8812  0.6204 
Pb:  0.8313  0.1687  0.7635 
Cl:  0.5692  0.4308  0.8096 
O:  0.7998  0.2002  0.4095 
H:  0.8812  0.1188  0.3796 
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
Ag
45
45
45
45
3.503e+40
5.7
3.639e+40
5.9
7.143e+40
11.6
5
Bg
56
56
56
56
5.789e+40
9.4
6.338e+40
10.3
1.213e+41
19.7
6
Bu
77
80
77
80
7
Au
80
80
84
84
8
Ag
84
84
104
104
9.642e+40
15.7
9.212e+40
15.0
1.885e+41
30.7
9
Bg
104
104
112
109
2.513e+41
40.9
3.638e+41
59.1
6.151e+41
100.0
10
Ag
112
112
120
112
1.649e+41
26.8
2.258e+40
3.7
1.875e+41
30.5
11
Bu
120
141
141
138
12
Ag
141
210
153
141
2.467e+41
40.1
1.941e+41
31.6
4.408e+41
71.7
13
Au
251
251
292
251
14
Bu
292
293
293
293
15
Bg
293
296
296
294
2.625e+40
4.3
4.306e+40
7.0
6.930e+40
11.3
16
Ag
296
298
297
296
1.301e+41
21.2
2.907e+40
4.7
1.592e+41
25.9
17
Bu
320
324
320
339
18
Ag
339
339
339
367
1.165e+41
18.9
3.369e+40
5.5
1.501e+41
24.4
19
Bg
533
533
533
533
7.183e+40
11.7
1.106e+41
18.0
1.824e+41
29.7
20
Au
560
560
631
560
21
Bu
679
679
679
704
22
Ag
765
765
765
765
6.291e+40
10.2
4.741e+40
7.7
1.103e+41
17.9
23
Ag
3503
3503
3503
3503
4.279e+41
69.6
1.721e+40
2.8
4.451e+41
72.4
24
Bu
3507
3515
3507
3508
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.