-    CHRYSOBERYL     -    Al2BeO4

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 
Lattice parameters (Å):  9.4040  5.4760  4.4270 
Angles (°):  90.0  90.0  90.0 

Symmetry (theoretical): 

Space group:  62  Pnma 
Lattice parameters (Å):  9.2531  5.3850  4.3452 
Angles (°):  90.0  90.0  90.0 

Cell contents: 

Number of atoms:  28 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Al:  0.0000  0.0000  0.0000 
Al:  0.2726  0.2500  0.9947 
Be:  0.0922  0.2500  0.4322 
O:  0.0901  0.2500  0.7851 
O:  0.4334  0.2500  0.2409 
O:  0.1632  0.0162  0.2573 
Al:  0.5000  0.0000  0.5000 
Al:  0.2274  0.7500  0.4947 
Be:  0.4078  0.7500  0.9322 
O:  0.4099  0.7500  0.2851 
O:  0.0666  0.7500  0.7409 
O:  0.3368  0.9838  0.7573 
Al:  0.0000  0.5000  0.0000 
Al:  0.7274  0.7500  0.0053 
Be:  0.9078  0.7500  0.5678 
O:  0.9099  0.7500  0.2149 
O:  0.5666  0.7500  0.7591 
O:  0.8368  0.5162  0.7427 
Al:  0.5000  0.5000  0.5000 
Al:  0.7726  0.2500  0.5053 
Be:  0.5922  0.2500  0.0678 
O:  0.5901  0.2500  0.7149 
O:  0.9334  0.2500  0.2591 
O:  0.6632  0.4838  0.2427 
O:  0.8368  0.9838  0.7427 
O:  0.6632  0.0162  0.2427 
O:  0.1632  0.4838  0.2573 
O:  0.3368  0.5162  0.7573 
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
Au
163
163
163
163
5
B3u
204
204
204
204
6
B3g
235
235
235
235
2.304e+36
0.0
3.167e+36
0.0
5.471e+36
0.1
7
A1g
243
243
243
243
2.191e+38
3.2
1.802e+37
0.3
2.371e+38
3.5
8
Au
285
285
285
285
9
B2u
290
290
291
290
10
B1g
297
297
297
297
9.249e+36
0.1
1.272e+37
0.2
2.197e+37
0.3
11
B1u
322
322
322
323
12
Au
329
329
329
329
13
B2g
346
346
346
346
6.982e+35
0.0
9.600e+35
0.0
1.658e+36
0.0
14
A1g
351
351
351
351
5.699e+38
8.4
2.079e+37
0.3
5.907e+38
8.7
15
B2u
356
356
357
356
16
B3g
359
359
359
359
1.182e+38
1.7
1.625e+38
2.4
2.808e+38
4.1
17
B2g
360
360
360
361
4.581e+37
0.7
6.299e+37
0.9
1.088e+38
1.6
18
B1u
361
361
361
361
3.070e+37
0.5
4.222e+37
0.6
7.292e+37
1.1
19
B2u
361
361
366
364
3.950e+37
0.6
5.431e+37
0.8
9.381e+37
1.4
20
Au
366
366
372
366
21
B1u
372
372
375
375
22
A1g
375
375
378
379
6.212e+38
9.2
1.390e+38
2.1
7.602e+38
11.2
23
B3u
379
384
379
381
24
B1g
398
398
398
398
6.647e+37
1.0
9.140e+37
1.3
1.579e+38
2.3
25
B2g
423
423
423
423
4.433e+38
6.5
6.095e+38
9.0
1.053e+39
15.5
26
B3u
427
437
427
427
27
B2g
437
440
437
437
1.670e+38
2.5
2.296e+38
3.4
3.966e+38
5.9
28
B3g
440
445
440
440
3.820e+37
0.6
5.253e+37
0.8
9.073e+37
1.3
29
B1g
445
446
445
445
2.017e+38
3.0
2.773e+38
4.1
4.790e+38
7.1
30
B2u
446
448
448
446
31
B1u
448
450
452
453
32
A1g
458
458
458
458
2.301e+38
3.4
1.726e+38
2.5
4.027e+38
5.9
33
Au
459
459
459
459
34
A1g
476
476
476
476
4.755e+38
7.0
2.776e+38
4.1
7.531e+38
11.1
35
B3g
477
477
477
477
8.733e+38
12.9
1.201e+39
17.7
2.074e+39
30.6
36
Au
492
492
492
492
37
B3u
494
501
494
494
38
B2u
501
504
504
501
39
B1g
504
509
509
504
4.432e+38
6.5
6.094e+38
9.0
1.053e+39
15.5
40
B1u
509
518
518
509
41
B2g
518
518
518
518
7.865e+38
11.6
1.081e+39
16.0
1.868e+39
27.6
42
B3u
518
520
520
518
43
B1g
520
522
522
520
1.413e+37
0.2
1.942e+37
0.3
3.355e+37
0.5
44
B1u
522
525
522
525
45
A1g
525
538
525
540
5.669e+38
8.4
3.324e+38
4.9
8.993e+38
13.3
46
B3u
540
545
540
543
47
Au
545
547
545
545
48
B2u
547
550
550
547
49
B1u
550
552
552
552
50
B2g
552
564
567
567
5.963e+38
8.8
8.200e+38
12.1
1.416e+39
20.9
51
B3g
567
567
568
568
2.255e+38
3.3
3.101e+38
4.6
5.357e+38
7.9
52
B3u
568
579
602
602
53
B3u
602
605
602
602
54
B1u
605
610
605
610
55
B2u
610
614
614
614
56
Au
614
623
616
623
57
Au
623
626
623
623
58
A1g
626
641
626
626
2.413e+38
3.6
1.743e+38
2.6
4.155e+38
6.1
59
B2u
641
642
642
641
60
B1u
642
650
650
650
61
A1g
650
652
652
652
8.306e+38
12.3
2.603e+38
3.8
1.091e+39
16.1
62
B2g
652
658
658
658
1.915e+38
2.8
2.633e+38
3.9
4.548e+38
6.7
63
B1g
658
663
659
666
1.882e+37
0.3
2.587e+37
0.4
4.469e+37
0.7
64
B3u
666
677
666
677
65
B3g
677
685
677
701
5.656e+38
8.3
7.777e+38
11.5
1.343e+39
19.8
66
B2g
701
701
701
714
4.532e+36
0.1
6.231e+36
0.1
1.076e+37
0.2
67
B2u
714
714
718
715
68
A1g
718
718
731
718
4.033e+38
5.9
1.760e+38
2.6
5.793e+38
8.5
69
B1u
731
731
746
731
70
B3u
746
750
750
746
71
B3g
750
758
759
750
2.593e+38
3.8
3.566e+38
5.3
6.159e+38
9.1
72
B2g
759
759
769
759
1.141e+37
0.2
1.569e+37
0.2
2.710e+37
0.4
73
B3u
769
777
777
769
74
B1u
777
780
780
780
75
A1g
780
782
785
785
2.006e+39
29.6
1.365e+37
0.2
2.020e+39
29.8
76
B3u
785
794
794
794
77
Au
794
823
823
811
78
B1g
823
834
834
823
4.851e+38
7.2
6.670e+38
9.8
1.152e+39
17.0
79
B2g
834
920
920
834
1.401e+37
0.2
1.927e+37
0.3
3.328e+37
0.5
80
B1u
920
937
937
924
81
A1g
937
940
945
937
6.685e+39
98.6
9.404e+37
1.4
6.779e+39
100.0
82
B2g
945
945
951
945
6.844e+36
0.1
9.410e+36
0.1
1.625e+37
0.2
83
B1u
951
951
958
966
84
B3u
966
973
966
1089
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.