-    WEBERITE     -    Na2MgAlF7

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:  74  Imma 
Lattice parameters (Å):  7.0600  10.0000  7.3030 
Angles (°):  90  90  90 

Symmetry (theoretical): 

Space group:  74  Imma 
Lattice parameters (Å):  7.1260  7.1260  7.1260 
Angles (°):  90  90  90 

Cell contents: 

Number of atoms:  22 
Number of atom types:  4 
Chemical composition:  0 

Atomic positions (theoretical):

Na:  0.0000  0.0000  0.0000 
Na:  0.0814  0.8314  0.2500 
Mg:  0.5000  0.5000  0.5000 
Al:  0.5000  0.5000  0.0000 
F:  0.3814  0.1314  0.2500 
F:  0.1613  0.7259  0.4354 
F:  0.8222  0.6263  0.5756 
Na:  0.5000  0.0000  0.5000 
Mg:  0.5000  0.0000  0.0000 
Al:  0.0000  0.5000  0.5000 
F:  0.7906  0.7259  0.0646 
F:  0.5507  0.2466  0.9244 
Na:  0.9186  0.1686  0.7500 
F:  0.6186  0.8686  0.7500 
F:  0.2094  0.2741  0.9354 
F:  0.4493  0.3737  0.6959 
F:  0.8387  0.2741  0.5646 
F:  0.1778  0.7534  0.8041 
F:  0.1778  0.3737  0.4244 
F:  0.4493  0.7534  0.0756 
F:  0.5507  0.6263  0.3041 
F:  0.8222  0.2466  0.1959 
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
B3u
-124
-112
-124
-124
2
ac
0
0
0
0
3
ac
0
0
0
0
4
ac
0
0
0
0
5
B2u
24
24
55
24
6
B2g
55
55
59
55
1.350e+38
3.4
1.857e+38
4.6
3.207e+38
8.0
7
B1u
59
59
59
59
6.112e+37
1.5
8.404e+37
2.1
1.452e+38
3.6
8
B1g
59
59
76
60
9
Au
76
76
84
76
10
B3u
89
114
89
89
11
B3g
114
115
114
114
1.074e+37
0.3
1.477e+37
0.4
2.552e+37
0.6
12
B2g
115
129
115
115
9.744e+37
2.4
1.340e+38
3.3
2.314e+38
5.8
13
Au
129
145
129
129
14
B1g
145
148
145
145
4.415e+37
1.1
6.071e+37
1.5
1.049e+38
2.6
15
A1g
151
151
151
151
7.182e+38
17.9
1.273e+38
3.2
8.455e+38
21.1
16
B1u
152
152
152
153
17
B2u
153
153
158
158
18
B3g
158
158
160
162
1.101e+37
0.3
1.513e+37
0.4
2.614e+37
0.7
19
B2u
162
162
165
165
20
B2g
168
168
168
168
1.997e+37
0.5
2.745e+37
0.7
4.742e+37
1.2
21
B3u
179
181
179
179
22
B1u
185
185
185
185
23
B2u
185
185
185
185
24
Ag
203
203
203
203
8.161e+38
20.4
2.835e+37
0.7
8.445e+38
21.1
25
B2u
203
203
205
203
26
B3u
206
214
206
206
27
B3u
240
241
240
240
28
B1u
241
241
241
241
29
Au
241
256
241
245
30
B3g
256
261
256
256
1.587e+38
4.0
2.182e+38
5.4
3.768e+38
9.4
31
Au
262
262
262
262
32
B1g
285
285
285
285
1.146e+38
2.9
1.576e+38
3.9
2.722e+38
6.8
33
B1u
288
288
288
292
34
B3u
292
299
292
298
35
B2u
299
301
300
299
36
B2u
301
304
304
301
37
B1u
304
306
306
306
38
A1g
306
318
320
320
3.943e+38
9.8
3.527e+37
0.9
4.296e+38
10.7
39
B3g
320
320
326
324
1.716e+36
0.0
2.360e+36
0.1
4.076e+36
0.1
40
B2g
326
326
330
326
1.027e+38
2.6
1.412e+38
3.5
2.439e+38
6.1
41
A1g
363
363
363
363
8.673e+38
21.6
4.672e+37
1.2
9.140e+38
22.8
42
A1g
372
372
372
372
1.711e+38
4.3
5.313e+36
0.1
1.764e+38
4.4
43
B1u
383
383
383
395
44
B2u
395
395
405
398
45
B3g
405
405
406
405
4.789e+37
1.2
6.585e+37
1.6
1.137e+38
2.8
46
B2g
406
406
412
406
4.496e+36
0.1
6.182e+36
0.2
1.068e+37
0.3
47
B1g
412
412
418
412
1.218e+38
3.0
1.674e+38
4.2
2.892e+38
7.2
48
B1u
418
418
443
423
49
B2u
456
456
456
456
50
B3g
464
464
464
464
1.650e+37
0.4
2.269e+37
0.6
3.919e+37
1.0
51
B3u
466
467
466
466
52
B2u
469
469
470
469
53
B1u
471
471
471
479
54
A1g
479
479
479
479
3.458e+38
8.6
9.973e+37
2.5
4.455e+38
11.1
55
Au
484
484
484
484
56
B1u
529
529
529
541
57
B2g
541
541
541
551
6.470e+37
1.6
8.896e+37
2.2
1.537e+38
3.8
58
B3u
554
564
554
554
59
Au
564
565
564
564
60
B2u
565
581
581
565
61
B1u
581
585
585
584
62
A1g
585
587
587
585
3.972e+39
99.1
3.665e+37
0.9
4.008e+39
100.0
63
B3g
587
611
613
587
5.112e+36
0.1
7.029e+36
0.2
1.214e+37
0.3
64
B3u
613
653
627
613
65
B1u
653
663
653
663
66
B2u
663
667
694
729
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.