-    BRUCITE     -    Mg(OH)2

 

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:  147  P-3 
Lattice parameters (Å):  6.9740  13.0860  8.0800 
Angles (°):  90  90  120 

Symmetry (theoretical): 

Space group:  147  P-3 
Lattice parameters (Å):  5.4546  5.4546  5.0072 
Angles (°):  90  109.21  90 

Cell contents: 

Number of atoms:  15 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Mg:  0.0000  0.0000  0.0000 
Mg:  0.3333  0.6667  0.0026 
Mg:  0.6667  0.3333  0.9974 
O:  0.0010  0.6672  0.7959 
O:  0.9990  0.3328  0.2041 
O:  0.6662  0.9990  0.7959 
O:  0.3338  0.0010  0.2041 
O:  0.3328  0.3338  0.7959 
O:  0.6672  0.6662  0.2041 
H:  0.0075  0.6704  0.6027 
H:  0.9925  0.3296  0.3973 
H:  0.6630  0.9925  0.6027 
H:  0.3370  0.0075  0.3973 
H:  0.3296  0.3370  0.6027 
H:  0.6704  0.6630  0.3973 
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
40
40
40
40
5
47
47
47
47
6
261
261
261
261
7
261
261
261
261
8
261
261
261
261
9
261
261
261
261
10
263
263
263
263
11
263
263
263
263
12
333
333
333
333
13
333
333
333
333
14
340
340
340
340
1.663e+40
0.2
6.313e+38
0.0
1.726e+40
0.2
15
340
340
340
340
16
340
340
340
340
5.887e+38
0.0
3.245e+37
0.0
6.212e+38
0.0
17
340
340
340
340
18
354
354
354
354
19
354
371
371
354
20
371
371
371
371
7.482e+42
90.8
7.586e+41
9.2
8.241e+42
100.0
21
371
372
372
371
22
406
406
406
406
23
406
406
406
406
24
406
406
406
406
25
406
406
406
406
26
417
417
417
417
27
417
423
423
417
28
423
450
450
423
29
450
452
452
450
30
452
488
488
452
31
488
667
667
591
32
667
667
667
667
33
667
675
675
667
34
675
675
675
675
35
675
706
706
675
36
706
706
706
706
37
706
714
714
706
38
886
886
886
886
39
887
887
887
887
40
3624
3624
3624
3624
41
3634
3634
3634
3634
42
3634
3634
3634
3634
43
3634
3634
3634
3634
44
3634
3634
3634
3634
45
3663
3663
3663
3675
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.