-    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  90  90 

Symmetry (theoretical): 

Space group:  62  Pnma 
Lattice parameters (Å):  5.1824  5.3285  7.4119 
Angles (°):  90  90  90 

Cell contents: 

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

Atomic positions (theoretical):

Na:  0.9871  0.0500  0.2500 
Mg:  0.0000  0.5000  0.0000 
F:  0.0887  0.4731  0.2500 
F:  0.7032  0.2941  0.0464 
Na:  0.4871  0.4500  0.7500 
Mg:  0.5000  1.0000  0.0000 
F:  0.5887  0.0269  0.7500 
F:  0.2032  0.2059  0.9536 
Na:  0.0129  0.9500  0.7500 
Mg:  0.0000  0.5000  0.5000 
F:  0.9113  0.5269  0.7500 
F:  0.2968  0.7059  0.5464 
Na:  0.5129  0.5500  0.2500 
Mg:  0.5000  1.0000  0.5000 
F:  0.4113  0.9731  0.2500 
F:  0.7968  0.7941  0.4536 
F:  0.2968  0.7059  0.9536 
F:  0.7968  0.7941  0.0464 
F:  0.7032  0.2941  0.4536 
F:  0.2032  0.2059  0.5464 
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
A1g
100
100
100
100
1.026e+38
11.0
5.781e+37
6.2
1.604e+38
17.2
5
Au
105
105
105
105
6
B1u
113
113
113
134
7
B3g
135
135
135
135
1.364e+37
1.5
1.876e+37
2.0
3.241e+37
3.5
8
B1g
136
136
136
136
1.477e+38
15.9
2.031e+38
21.8
3.508e+38
37.6
9
A1g
150
150
150
150
3.188e+38
34.2
1.004e+38
10.8
4.192e+38
45.0
10
B2u
153
153
155
153
11
B3u
155
158
158
155
12
B2g
158
158
160
158
7.889e+37
8.5
1.085e+38
11.6
1.874e+38
20.1
13
Au
164
164
164
164
14
B1g
167
167
167
167
3.582e+37
3.8
4.925e+37
5.3
8.507e+37
9.1
15
B3g
179
179
179
179
1.849e+36
0.2
2.543e+36
0.3
4.392e+36
0.5
16
B3u
179
187
179
179
17
B1u
187
195
187
195
18
A1g
195
201
195
201
5.323e+38
57.1
1.007e+37
1.1
5.424e+38
58.2
19
B2u
201
202
208
210
20
B2u
210
210
211
211
21
Au
211
211
212
212
22
B1g
212
212
226
218
1.311e+37
1.4
1.802e+37
1.9
3.112e+37
3.3
23
A1g
226
226
227
226
1.665e+38
17.9
1.109e+38
11.9
2.774e+38
29.8
24
Au
227
227
228
227
25
B3u
228
229
228
228
26
B2g
234
234
234
234
3.247e+37
3.5
4.465e+37
4.8
7.711e+37
8.3
27
B2u
243
243
246
243
28
A1g
258
258
258
258
8.852e+38
95.0
4.652e+37
5.0
9.317e+38
100.0
29
B3u
260
265
260
260
30
B1g
265
265
265
265
1.270e+37
1.4
1.747e+37
1.9
3.017e+37
3.2
31
B3g
269
269
269
269
1.644e+37
1.8
2.260e+37
2.4
3.904e+37
4.2
32
B3u
289
289
289
289
33
B1u
289
292
289
290
34
B2u
295
295
295
295
35
Au
297
297
297
297
36
B1u
309
309
309
318
37
B2u
318
318
323
323
38
B1g
323
323
324
324
3.374e+36
0.4
4.639e+36
0.5
8.013e+36
0.9
39
B2g
324
324
327
327
1.077e+37
1.2
1.481e+37
1.6
2.559e+37
2.7
40
B3u
327
331
331
331
41
A1g
331
343
343
343
6.458e+37
6.9
4.573e+37
4.9
1.103e+38
11.8
42
B1g
343
376
379
362
2.283e+37
2.5
3.139e+37
3.4
5.423e+37
5.8
43
B3g
390
390
390
390
5.117e+37
5.5
7.036e+37
7.6
1.215e+38
13.0
44
B2g
393
393
393
393
1.772e+38
19.0
2.425e+38
26.0
4.197e+38
45.0
45
Ag
393
393
393
393
1.095e+38
11.7
7.260e+37
7.8
1.821e+38
19.5
46
B3u
423
424
423
423
47
B1u
424
424
424
424
48
Au
424
441
424
434
49
B2u
461
461
461
461
50
B3u
467
467
467
467
51
B3g
489
489
489
489
7.845e+36
0.8
1.079e+37
1.2
1.863e+37
2.0
52
B1g
501
501
501
501
53
B2u
503
503
504
503
54
B1u
512
512
512
515
55
B2u
519
519
520
519
56
Au
520
520
521
520
57
B2g
521
521
524
521
58
B3u
524
525
525
524
59
Au
525
531
531
525
60
B1u
531
617
618
623
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.