-    NEIGHBORITE     -    NaMgF3

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):  5.3603  5.4884  7.6660 
Angles (°):  90.0  90.0  90.0 

Symmetry (theoretical): 

Space group:  62  Pnma 
Lattice parameters (Å):  5.1838  5.3623  7.4400 
Angles (°):  90.0  90.0  90.0 

Cell contents: 

Number of atoms:  20 
Number of atom types:  3 
Chemical composition:  0 

Atomic positions (theoretical):

Na:  0.9845  0.0558  0.2500 
Mg:  0.0000  0.5000  0.0000 
F:  0.1007  0.4654  0.2500 
F:  0.6988  0.2979  0.0529 
Na:  0.4845  0.4442  0.7500 
Mg:  0.5000  0.0000  0.0000 
F:  0.6007  0.0346  0.7500 
F:  0.1988  0.2021  0.9471 
Na:  0.0155  0.9442  0.7500 
Mg:  0.0000  0.5000  0.5000 
F:  0.8993  0.5346  0.7500 
F:  0.3012  0.7021  0.5529 
Na:  0.5155  0.5558  0.2500 
Mg:  0.5000  0.0000  0.5000 
F:  0.3993  0.9654  0.2500 
F:  0.8012  0.7979  0.4471 
F:  0.3012  0.7021  0.9471 
F:  0.8012  0.7979  0.0529 
F:  0.6988  0.2979  0.4471 
F:  0.1988  0.2021  0.5529 
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
ac
0
0
0
0
2
ac
0
0
0
0
3
ac
0
0
0
0
4
B1u
99
99
99
99
5
Au
99
99
99
102
6
A1g
102
102
102
129
1.302e+38
15.1
5.678e+37
6.6
1.870e+38
21.7
7
B3g
132
132
132
132
1.366e+37
1.6
1.878e+37
2.2
3.245e+37
3.8
8
B2g
144
144
144
144
9.634e+37
11.2
1.325e+38
15.4
2.288e+38
26.6
9
B1g
147
147
147
147
2.667e+37
3.1
3.667e+37
4.3
6.334e+37
7.4
10
B1g
147
147
155
147
1.102e+38
12.8
1.515e+38
17.6
2.616e+38
30.4
11
B3u
156
158
156
156
12
A1g
159
159
159
159
3.151e+38
36.6
8.892e+37
10.3
4.040e+38
47.0
13
Au
163
163
163
163
14
B1g
169
169
169
169
8.339e+37
9.7
1.147e+38
13.3
1.981e+38
23.0
15
B3g
173
173
173
173
1.735e+36
0.2
2.386e+36
0.3
4.120e+36
0.5
16
B3u
174
183
174
174
17
B1u
183
196
183
196
18
A1g
196
197
196
198
8.320e+38
96.8
2.790e+37
3.2
8.599e+38
100.0
19
B2u
198
198
202
202
20
Au
202
202
204
210
21
B2u
210
210
218
210
22
Au
218
218
218
218
23
B1g
218
218
224
218
5.522e+36
0.6
7.593e+36
0.9
1.311e+37
1.5
24
B3u
230
231
230
230
25
A1g
231
231
231
231
1.951e+38
22.7
1.164e+38
13.5
3.114e+38
36.2
26
B2g
232
232
232
232
3.692e+37
4.3
5.076e+37
5.9
8.768e+37
10.2
27
B2u
242
242
246
242
28
B1g
264
264
264
264
1.765e+37
2.1
2.427e+37
2.8
4.192e+37
4.9
29
B3u
265
268
265
265
30
B1g
268
268
268
268
4.184e+38
48.7
2.778e+37
3.2
4.462e+38
51.9
31
B1g
268
268
268
268
8.194e+38
95.3
3.246e+37
3.8
8.519e+38
99.1
32
B1u
283
283
283
283
33
Au
292
292
292
292
34
B3u
294
296
294
294
35
B2u
296
298
297
296
36
B1u
298
298
298
311
37
B2u
311
311
318
318
38
B2g
318
318
319
319
8.138e+36
0.9
1.119e+37
1.3
1.933e+37
2.2
39
B1g
319
319
322
322
4.540e+36
0.5
6.243e+36
0.7
1.078e+37
1.3
40
B3u
322
325
325
325
41
A1g
325
339
339
339
5.843e+37
6.8
4.239e+37
4.9
1.008e+38
11.7
42
B1g
339
364
371
349
1.937e+37
2.3
2.664e+37
3.1
4.601e+37
5.4
43
B2g
384
384
384
384
7.086e+37
8.2
1.025e+38
11.9
1.734e+38
20.2
44
B3g
384
384
384
384
2.209e+38
25.7
3.038e+38
35.3
5.247e+38
61.0
45
A1g
389
389
389
389
1.236e+38
14.4
7.616e+37
8.9
1.997e+38
23.2
46
B3u
415
423
415
415
47
B1u
423
423
423
423
48
Au
423
438
423
433
49
B2u
459
459
459
459
50
B3u
466
466
466
466
51
B3g
479
479
479
479
1.185e+37
1.4
1.630e+37
1.9
2.815e+37
3.3
52
B1g
494
494
494
494
53
B2u
500
500
502
500
54
B1u
503
503
503
508
55
B2g
510
510
510
510
7.962e+35
0.1
1.095e+36
0.1
1.891e+36
0.2
56
Au
510
510
510
510
57
B2u
513
513
515
513
58
Au
515
515
519
515
59
B1u
519
519
519
519
60
B3u
519
614
615
614
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.