-    GAHNITE     -    ZnOAl2O3

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:  227  Fd-3m 
Lattice parameters (Å):  8.0897  8.0897  8.0897 
Angles (°):  90  90  90 

Symmetry (theoretical): 

Space group:  227  Fd-3m 
Lattice parameters (Å):  5.7937  5.7937  5.7937 
Angles (°):  60  60  60 

Cell contents: 

Number of atoms:  14 
Number of atom types:  3 
Chemical composition:  0 

Atomic positions (theoretical):

Al:  0.1250  0.1250  0.1250 
Al:  0.8750  0.8750  0.8750 
Zn:  0.5000  0.5000  0.5000 
Zn:  0.5000  0.5000  0.0000 
Zn:  0.5000  0.0000  0.5000 
Zn:  0.0000  0.5000  0.5000 
O:  0.2496  0.2496  0.2496 
O:  0.2496  0.2496  0.7511 
O:  0.2496  0.7511  0.2496 
O:  0.7511  0.2496  0.2496 
O:  0.7504  0.7504  0.2489 
O:  0.7504  0.7504  0.7504 
O:  0.7504  0.2489  0.7504 
O:  0.2489  0.7504  0.7504 
Atom type  X  Y  Z 

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
-8
-8
-8
-8
2
-5
-5
-5
-5
3
-4
-4
-4
-4
4
114
114
114
114
1.228e+46
0.0
1.142e+46
0.0
2.370e+46
0.0
5
117
117
117
117
6.778e+45
0.0
6.431e+45
0.0
1.321e+46
0.0
6
122
122
122
122
7
188
188
188
188
1.515e+47
0.0
6.744e+46
0.0
2.189e+47
0.0
8
189
189
189
189
8.143e+46
0.0
5.674e+46
0.0
1.382e+47
0.0
9
191
191
191
191
1.671e+46
0.0
6.602e+45
0.0
2.331e+46
0.0
10
192
192
192
192
7.537e+46
0.0
6.034e+46
0.0
1.357e+47
0.0
11
198
198
198
198
2.256e+46
0.0
1.349e+46
0.0
3.605e+46
0.0
12
219
222
220
220
3.047e+49
3.3
5.088e+49
5.5
8.135e+49
8.9
13
230
230
230
230
1.046e+50
11.4
1.656e+50
18.0
2.702e+50
29.4
14
232
232
232
232
1.166e+50
12.7
9.803e+49
10.7
2.147e+50
23.4
15
235
237
236
236
8.207e+49
8.9
1.291e+50
14.1
2.112e+50
23.0
16
241
242
242
241
2.606e+49
2.8
3.980e+49
4.3
6.586e+49
7.2
17
248
249
252
248
4.526e+49
4.9
3.399e+49
3.7
7.925e+49
8.6
18
255
256
256
255
5.134e+50
56.0
3.861e+50
42.1
8.996e+50
98.1
19
274
274
274
274
5.242e+50
57.1
3.932e+50
42.9
9.174e+50
100.0
20
302
302
302
302
1.012e+47
0.0
6.651e+46
0.0
1.677e+47
0.0
21
304
304
304
304
7.489e+46
0.0
6.114e+46
0.0
1.360e+47
0.0
22
305
305
305
305
2.906e+46
0.0
2.225e+46
0.0
5.132e+46
0.0
23
312
312
313
312
6.937e+45
0.0
5.620e+45
0.0
1.256e+46
0.0
24
365
365
365
365
25
377
377
377
377
26
382
382
382
382
7.518e+45
0.0
3.376e+45
0.0
1.089e+46
0.0
27
391
391
392
391
3.114e+47
0.0
1.507e+47
0.0
4.621e+47
0.1
28
393
393
393
393
8.017e+46
0.0
6.011e+46
0.0
1.403e+47
0.0
29
395
395
395
395
3.921e+46
0.0
4.092e+46
0.0
8.012e+46
0.0
30
467
467
467
467
31
476
477
476
479
32
481
481
481
481
3.050e+47
0.0
2.591e+47
0.0
5.641e+47
0.1
33
487
488
488
487
9.248e+46
0.0
7.635e+46
0.0
1.688e+47
0.0
34
491
491
491
491
2.026e+47
0.0
2.848e+47
0.0
4.874e+47
0.1
35
601
601
601
601
3.799e+49
4.1
5.457e+49
5.9
9.256e+49
10.1
36
603
603
603
606
4.016e+49
4.4
4.557e+49
5.0
8.573e+49
9.3
37
608
608
608
608
3.727e+49
4.1
5.745e+49
6.3
9.472e+49
10.3
38
646
646
647
646
1.033e+47
0.0
6.246e+46
0.0
1.658e+47
0.0
39
647
647
647
647
1.476e+47
0.0
6.668e+46
0.0
2.142e+47
0.0
40
649
649
649
649
5.441e+46
0.0
3.636e+46
0.0
9.077e+46
0.0
41
655
659
655
657
42
695
695
695
695
1.015e+50
11.1
4.610e+45
0.0
1.015e+50
11.1
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.