-    NEIGHBORITE     -    NaMgF3

 

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):  5.3603  5.4884  7.6660 
Angles (°):  90  90  90 

Symmetry (theoretical): 

Space group:  62  Pnma 
Lattice parameters (Å):  4.8505  5.1169  7.0332 
Angles (°):  90  90  90 

Cell contents: 

Number of atoms:  20 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Na:  0.9791  0.0686  0.2500 
Mg:  0.0000  0.5000  0.0000 
F:  0.1027  0.4718  0.2500 
F:  0.6894  0.3038  0.0520 
Na:  0.4791  0.4314  0.7500 
Mg:  0.5000  0.0000  0.0000 
F:  0.6027  0.0282  0.7500 
F:  0.1894  0.1962  0.9480 
Na:  0.0209  0.9314  0.7500 
Mg:  0.0000  0.5000  0.5000 
F:  0.8973  0.5282  0.7500 
F:  0.3106  0.6962  0.5520 
Na:  0.5209  0.5686  0.2500 
Mg:  0.5000  0.0000  0.5000 
F:  0.3973  0.9718  0.2500 
F:  0.8106  0.8038  0.4480 
F:  0.3106  0.6962  0.9480 
F:  0.8106  0.8038  0.0520 
F:  0.6894  0.3038  0.4480 
F:  0.1894  0.1962  0.5520 
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
118
118
118
118
5
B1u
160
160
160
172
6
A1g
172
172
172
174
1.061e+38
13.7
7.050e+37
9.1
1.766e+38
22.8
7
B3u
174
174
174
176
8
A1g
188
188
188
188
4.641e+38
60.0
6.819e+37
8.8
5.323e+38
68.8
9
B1g
189
189
189
189
3.971e+37
5.1
5.461e+37
7.1
9.432e+37
12.2
10
B2u
192
192
200
192
11
B3g
200
200
200
200
1.019e+37
1.3
1.401e+37
1.8
2.420e+37
3.1
12
B1g
217
217
217
217
1.588e+38
20.5
2.183e+38
28.2
3.770e+38
48.7
13
Au
218
218
218
218
14
B3g
218
218
218
218
6.804e+36
0.9
9.356e+36
1.2
1.616e+37
2.1
15
B2g
224
224
224
224
5.264e+37
6.8
7.238e+37
9.4
1.250e+38
16.2
16
Au
231
231
231
231
17
B3u
239
246
239
239
18
B1u
246
247
246
247
19
A1g
247
248
247
248
5.342e+38
69.0
5.826e+37
7.5
5.925e+38
76.6
20
Au
248
252
248
257
21
B2u
263
263
266
263
22
B2u
266
266
275
266
23
B3u
275
276
276
275
24
B2g
276
276
276
276
1.036e+37
1.3
1.425e+37
1.8
2.461e+37
3.2
25
B1g
283
283
283
283
7.115e+36
0.9
9.783e+36
1.3
1.690e+37
2.2
26
A1g
283
283
283
283
1.406e+38
18.2
5.313e+37
6.9
1.937e+38
25.0
27
B2u
297
297
300
297
28
B1u
316
316
316
325
29
B3u
336
344
336
336
30
B1g
344
353
344
344
31
Au
355
355
355
355
32
B1u
359
359
359
368
33
B3g
368
368
368
390
2.524e+37
3.3
3.471e+37
4.5
5.995e+37
7.7
34
B3u
390
393
390
396
35
A1g
396
396
396
399
7.435e+38
96.1
3.036e+37
3.9
7.739e+38
100.0
36
B2u
399
399
403
403
37
B1g
403
403
406
408
38
B2u
408
408
410
410
39
B3u
410
413
413
413
40
B2g
413
421
421
414
1.937e+37
2.5
2.663e+37
3.4
4.599e+37
5.9
41
A1g
421
440
451
421
1.557e+38
20.1
9.910e+37
12.8
2.548e+38
32.9
42
B1g
451
451
462
451
2.490e+37
3.2
3.423e+37
4.4
5.913e+37
7.6
43
B3g
499
499
499
499
4.217e+37
5.4
5.799e+37
7.5
1.002e+38
12.9
44
A1g
504
504
504
504
1.243e+38
16.1
8.300e+37
10.7
2.073e+38
26.8
45
B2g
507
507
507
507
2.077e+38
26.8
2.856e+38
36.9
4.933e+38
63.7
46
B1u
510
510
510
515
47
B3u
515
517
515
517
48
Au
517
537
517
530
49
B2u
537
550
541
537
50
B3u
554
556
554
554
51
B2u
591
591
592
591
52
B3g
592
592
592
592
4.431e+36
0.6
6.092e+36
0.8
1.052e+37
1.4
53
B1g
596
596
596
596
54
B2g
619
619
619
619
3.507e+35
0.0
4.822e+35
0.1
8.328e+35
0.1
55
B1u
658
658
658
659
56
Au
660
660
660
660
57
B2u
662
662
664
662
58
B3u
664
682
682
664
59
Au
682
687
687
682
60
B1u
687
735
745
760
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.