-    JOHACHIDOLITE     -    CaAlB3O7

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:  67  Cmma 
Lattice parameters (Å):  7.9670  11.7230  4.3718 
Angles (°):  90  90  90 

Symmetry (theoretical): 

Space group:  67  Cmma 
Lattice parameters (Å):  7.7518  7.7518  4.3895 
Angles (°):  90  90  66.80 

Cell contents: 

Number of atoms:  24 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Ca:  0.5000  0.0000  0.0000 
Al:  0.0000  0.0000  0.0000 
Al:  0.2500  0.7500  0.5000 
B:  0.1248  0.1248  0.4196 
B:  0.2500  0.2500  0.3938 
O:  0.1168  0.1168  0.7447 
O:  0.2076  0.9375  0.2596 
Ca:  0.0000  0.5000  0.0000 
Al:  0.5000  0.5000  0.0000 
B:  0.3752  0.3752  0.4196 
O:  0.3832  0.3832  0.7447 
O:  0.2924  0.5625  0.2596 
B:  0.6248  0.6248  0.5804 
B:  0.7500  0.7500  0.6062 
O:  0.6168  0.6168  0.2553 
O:  0.4375  0.7076  0.7404 
B:  0.8752  0.8752  0.5804 
O:  0.8832  0.8832  0.2553 
O:  0.0625  0.7924  0.7404 
Al:  0.7500  0.2500  0.5000 
O:  0.7924  0.0625  0.7404 
O:  0.7076  0.4375  0.7404 
O:  0.5625  0.2924  0.2596 
O:  0.9375  0.2076  0.2596 
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
Au
-98
-98
-98
-98
2
B3u
-91
-87
-91
-91
3
B2g
-78
-78
-78
-78
4
B2u
-69
-69
-56
-69
5
B1u
-24
-24
-24
-1
6
B3u
-1
-1
0
0
7
B2u
0
0
0
0
8
B1u
0
0
1
20
9
B2u
52
52
84
52
6.138e+53
0.0
8.449e+53
0.0
1.459e+54
0.1
10
B3g
118
118
118
118
11
B3u
120
121
120
120
1.006e+56
5.9
1.384e+56
8.1
2.390e+56
14.0
12
B1u
143
143
143
152
2.990e+53
0.0
4.123e+53
0.0
7.113e+53
0.0
13
B1g
168
168
168
168
8.213e+55
4.8
1.165e+56
6.8
1.987e+56
11.6
14
Au
198
198
198
198
1.081e+55
0.6
1.489e+55
0.9
2.570e+55
1.5
15
B3g
203
203
203
203
16
B1u
210
210
210
212
9.710e+54
0.6
1.333e+55
0.8
2.304e+55
1.4
17
B2g
229
229
229
229
1.164e+54
0.1
1.691e+54
0.1
2.855e+54
0.2
18
B3u
235
237
235
235
1.112e+54
0.1
1.506e+54
0.1
2.617e+54
0.2
19
B1g
260
260
260
260
7.156e+56
42.0
9.899e+56
58.0
1.705e+57
100.0
20
B2u
270
270
278
270
8.731e+52
0.0
1.207e+53
0.0
2.080e+53
0.0
21
B2g
281
281
281
281
1.785e+52
0.0
2.825e+52
0.0
4.610e+52
0.0
22
Ag
289
289
289
289
7.718e+53
0.0
1.360e+53
0.0
9.078e+53
0.1
23
B3u
311
312
311
311
2.533e+53
0.0
3.473e+53
0.0
6.006e+53
0.0
24
Ag
313
313
313
313
4.538e+53
0.0
8.958e+52
0.0
5.434e+53
0.0
25
B2g
323
323
323
323
1.239e+56
7.3
1.704e+56
10.0
2.943e+56
17.3
26
B3g
327
327
327
327
1.528e+52
0.0
2.081e+52
0.0
3.609e+52
0.0
27
B1g
330
330
330
330
3.227e+56
18.9
4.437e+56
26.0
7.664e+56
44.9
28
Au
340
340
340
340
1.939e+54
0.1
2.668e+54
0.2
4.606e+54
0.3
29
B1u
353
353
353
353
4.138e+55
2.4
5.685e+55
3.3
9.823e+55
5.8
30
B2u
382
382
391
382
31
B3u
414
414
414
414
9.100e+51
0.0
1.231e+52
0.0
2.141e+52
0.0
32
B3u
425
425
425
425
1.233e+52
0.0
1.716e+52
0.0
2.949e+52
0.0
33
Au
429
429
429
429
34
B1u
436
436
436
442
1.381e+53
0.0
1.911e+53
0.0
3.293e+53
0.0
35
B1u
457
457
457
471
9.957e+51
0.0
1.441e+52
0.0
2.437e+52
0.0
36
B2u
476
476
477
476
37
Ag
498
498
498
498
3.805e+54
0.2
5.230e+54
0.3
9.035e+54
0.5
38
B1g
498
498
498
498
2.047e+56
12.0
2.587e+56
15.2
4.634e+56
27.2
39
Au
499
499
499
499
1.938e+54
0.1
2.180e+54
0.1
4.119e+54
0.2
40
B3g
501
501
501
501
9.471e+52
0.0
1.296e+53
0.0
2.243e+53
0.0
41
Ag
512
512
512
512
3.200e+54
0.2
1.786e+54
0.1
4.986e+54
0.3
42
B1u
520
520
520
523
1.831e+54
0.1
2.427e+54
0.1
4.258e+54
0.2
43
B3u
536
536
536
536
1.877e+52
0.0
2.421e+52
0.0
4.298e+52
0.0
44
B2g
539
539
539
539
45
B1u
561
561
561
574
8.559e+52
0.0
1.117e+53
0.0
1.973e+53
0.0
46
B2u
585
585
586
585
47
Au
617
617
617
617
48
B2u
631
631
640
631
49
B3g
644
644
644
644
50
B1u
686
686
686
686
51
B2u
690
690
694
690
52
B1g
697
697
697
697
2.538e+52
0.0
3.489e+52
0.0
6.027e+52
0.0
53
Ag
702
702
702
702
1.418e+53
0.0
5.444e+52
0.0
1.962e+53
0.0
54
B3g
721
721
721
721
55
B2g
737
737
737
737
56
B3u
753
753
753
753
57
B2g
804
804
804
804
1.269e+52
0.0
1.662e+52
0.0
2.931e+52
0.0
58
B3u
810
813
810
810
59
Ag
820
820
820
820
4.652e+53
0.0
6.192e+53
0.0
1.084e+54
0.1
60
B1g
821
821
821
821
7.454e+51
0.0
1.025e+52
0.0
1.770e+52
0.0
61
B2u
868
868
868
868
1.603e+53
0.0
2.204e+53
0.0
3.806e+53
0.0
62
B1u
868
868
873
870
4.161e+52
0.0
5.741e+52
0.0
9.902e+52
0.0
63
B3g
881
881
881
881
64
Au
934
934
934
934
1.878e+52
0.0
2.581e+52
0.0
4.459e+52
0.0
65
B1u
956
956
956
957
66
Ag
990
990
990
990
9.196e+53
0.1
9.299e+53
0.1
1.850e+54
0.1
67
B3g
1001
1001
1001
1001
68
B2u
1008
1008
1008
1008
69
B1u
1032
1032
1032
1051
1.916e+52
0.0
2.654e+52
0.0
4.570e+52
0.0
70
Ag
1065
1065
1065
1065
1.028e+55
0.6
6.208e+54
0.4
1.649e+55
1.0
71
B2u
1254
1254
1256
1254
5.599e+54
0.3
7.699e+54
0.5
1.330e+55
0.8
72
B3g
1256
1256
1256
1256
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.