-    DIASPORE     -    AlO(OH)

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:  62  Pnma_Pbnm 
Lattice parameters (Å):  4.4007  9.4253  2.8452 
Angles (°):  90.0  90.0  90.0 

Symmetry (theoretical): 

Space group:  62  Pnma_Pbnm 
Lattice parameters (Å):  4.2852  9.2555  2.7948 
Angles (°):  90.0  90.0  90.0 

Cell contents: 

Number of atoms:  16 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Al:  0.0489  0.8592  0.7500 
O:  0.6995  0.1962  0.7500 
O:  0.1991  0.0555  0.7500 
H:  0.4241  0.0969  0.7500 
Al:  0.5489  0.6408  0.2500 
O:  0.1995  0.3038  0.2500 
O:  0.6991  0.4445  0.2500 
H:  0.9241  0.4031  0.2500 
Al:  0.9511  0.1408  0.2500 
O:  0.3005  0.8038  0.2500 
O:  0.8009  0.9445  0.2500 
H:  0.5759  0.9031  0.2500 
Al:  0.4511  0.3592  0.7500 
O:  0.8005  0.6962  0.7500 
O:  0.3009  0.5555  0.7500 
H:  0.0759  0.5969  0.7500 
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
A1g
184
184
184
184
1.606e+38
0.1
5.994e+37
0.0
2.205e+38
0.1
5
B2g
197
197
197
197
2.423e+37
0.0
3.332e+37
0.0
5.755e+37
0.0
6
Au
209
209
209
209
7
B2u
262
262
262
262
8
B3g
298
298
298
298
2.486e+37
0.0
3.419e+37
0.0
5.905e+37
0.0
9
B1g
300
300
300
300
8.088e+38
0.4
1.112e+39
0.5
1.921e+39
0.9
10
B3u
353
356
353
353
11
A1g
356
358
356
356
7.135e+39
3.2
1.882e+39
0.8
9.017e+39
4.1
12
B1u
365
365
365
372
13
Au
372
372
372
382
14
B3g
382
382
382
383
1.427e+39
0.6
1.962e+39
0.9
3.389e+39
1.5
15
B1g
383
383
383
389
1.060e+38
0.0
1.458e+38
0.1
2.518e+38
0.1
16
B2g
400
400
400
400
4.907e+37
0.0
6.747e+37
0.0
1.165e+38
0.1
17
B3u
406
434
406
406
18
A1g
434
450
434
434
2.728e+40
12.3
2.536e+39
1.1
2.981e+40
13.4
19
B2u
450
459
459
450
20
B1g
459
482
508
459
2.769e+39
1.2
3.807e+39
1.7
6.576e+39
3.0
21
A1g
508
508
516
508
4.871e+39
2.2
2.384e+38
0.1
5.109e+39
2.3
22
B2u
517
517
524
517
23
B1u
524
524
530
530
24
B2g
530
530
543
543
3.492e+38
0.2
4.801e+38
0.2
8.293e+38
0.4
25
Au
543
543
553
553
26
B3u
553
553
553
553
27
B3g
553
553
587
587
8.285e+37
0.0
1.139e+38
0.1
1.968e+38
0.1
28
B1g
587
587
595
595
7.820e+37
0.0
1.075e+38
0.0
1.857e+38
0.1
29
B3u
595
615
615
615
30
A1g
615
653
646
659
1.734e+38
0.1
1.275e+38
0.1
3.009e+38
0.1
31
B3u
659
664
659
664
32
B2u
664
682
682
682
33
A1g
682
686
686
686
8.713e+39
3.9
2.761e+37
0.0
8.741e+39
3.9
34
B1g
686
724
687
724
1.239e+39
0.6
1.704e+39
0.8
2.943e+39
1.3
35
B2u
724
773
753
752
36
B1g
773
808
773
773
4.714e+39
2.1
6.482e+39
2.9
1.120e+40
5.0
37
Au
1108
1108
1108
1108
38
B1u
1113
1113
1113
1154
39
B2u
1154
1154
1171
1171
40
B3g
1171
1171
1177
1177
3.001e+38
0.1
4.126e+38
0.2
7.127e+38
0.3
41
B2g
1177
1177
1279
1189
2.344e+37
0.0
3.223e+37
0.0
5.566e+37
0.0
42
B3u
1279
1279
1279
1279
43
A1g
1311
1311
1311
1311
3.010e+39
1.4
7.673e+38
0.3
3.777e+39
1.7
44
B1g
1311
1311
1311
1311
2.073e+39
0.9
2.851e+39
1.3
4.924e+39
2.2
45
A1g
2474
2474
2474
2474
1.902e+41
85.7
3.183e+40
14.3
2.220e+41
100.0
46
B2u
2495
2495
2512
2495
47
B1g
2512
2512
2514
2512
4.006e+40
18.0
5.508e+40
24.8
9.514e+40
42.9
48
B3u
2514
2794
2572
2514
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.