-    Na2Mg(SO4)2     -    Na2Mg(SO4)2

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 ICSD database; code 249878 

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:  15  C2/c 
Lattice parameters (Å):  10.1010  8.2400  8.7300 
Angles (°):  90.0  114.640  90.0 

Symmetry (theoretical): 

Space group:  15  C2/c 
Lattice parameters (Å):  6.2840  6.2840  8.6606 
Angles (°):  67.88  112.11  101.71 

Cell contents: 

Number of atoms:  26 
Number of atom types:  4 
Chemical composition:  0 

Atomic positions (theoretical):

Mg:  0.0933  0.0933  0.2500 
Na:  0.3968  0.6686  0.0591 
S:  0.6083  0.9833  0.3171 
O:  0.7501  0.0269  0.4826 
O:  0.4114  0.1295  0.2304 
O:  0.5270  0.7398  0.3485 
O:  0.7445  0.0518  0.1980 
Na:  0.6686  0.3968  0.4409 
S:  0.9833  0.6083  0.1829 
O:  0.0269  0.7501  0.0174 
O:  0.1295  0.4114  0.2696 
O:  0.7398  0.5270  0.1515 
O:  0.0518  0.7445  0.3020 
Mg:  0.9067  0.9067  0.7500 
Na:  0.6032  0.3314  0.9409 
S:  0.3917  0.0167  0.6829 
O:  0.2499  0.9731  0.5174 
O:  0.5886  0.8705  0.7696 
O:  0.4730  0.2602  0.6515 
O:  0.2555  0.9482  0.8020 
Na:  0.3314  0.6032  0.5591 
S:  0.0167  0.3917  0.8171 
O:  0.9731  0.2499  0.9826 
O:  0.8705  0.5886  0.7304 
O:  0.2602  0.4730  0.8485 
O:  0.9482  0.2555  0.6980 
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
Bg
62
62
62
62
2.109e+37
0.0
2.255e+37
0.0
4.364e+37
0.0
5
Bu
73
73
73
78
6
Ag
79
79
79
79
6.286e+38
0.4
4.324e+38
0.3
1.061e+39
0.7
7
Ag
83
83
83
83
6.434e+38
0.4
4.501e+38
0.3
1.093e+39
0.7
8
Au
104
108
110
104
9
Ag
110
110
110
110
3.757e+38
0.2
7.649e+37
0.0
4.522e+38
0.3
10
Bu
112
118
118
115
11
Bg
118
119
119
118
2.970e+38
0.2
3.120e+38
0.2
6.090e+38
0.4
12
Au
133
135
135
133
13
Bg
135
135
136
135
8.704e+37
0.1
9.119e+37
0.1
1.782e+38
0.1
14
Au
137
137
137
137
15
Bu
137
138
138
137
16
Bg
144
144
144
144
1.481e+38
0.1
1.412e+38
0.1
2.893e+38
0.2
17
Ag
145
145
145
145
3.215e+39
2.0
3.190e+37
0.0
3.247e+39
2.0
18
Bg
151
151
151
151
9.403e+36
0.0
9.634e+36
0.0
1.904e+37
0.0
19
Ag
165
165
165
165
3.160e+39
2.0
2.404e+38
0.1
3.401e+39
2.1
20
Bu
166
166
166
177
21
Au
177
177
177
178
22
Au
181
181
181
181
23
Bg
187
187
187
187
1.890e+38
0.1
1.559e+38
0.1
3.449e+38
0.2
24
Ag
188
188
188
188
2.496e+38
0.2
1.726e+38
0.1
4.222e+38
0.3
25
Bu
192
192
192
196
26
Ag
203
203
203
203
6.059e+38
0.4
7.775e+37
0.0
6.837e+38
0.4
27
Au
204
205
205
204
28
Bg
207
207
207
207
1.021e+38
0.1
8.517e+37
0.1
1.873e+38
0.1
29
Bg
228
228
228
228
1.043e+38
0.1
1.086e+38
0.1
2.128e+38
0.1
30
Bu
232
234
233
234
31
Ag
235
235
235
235
4.233e+39
2.6
4.877e+37
0.0
4.282e+39
2.7
32
Au
236
252
254
236
33
Bg
256
256
256
256
5.868e+38
0.4
5.318e+38
0.3
1.119e+39
0.7
34
Bu
259
267
268
262
35
Au
280
280
280
280
36
Ag
281
281
282
281
2.817e+38
0.2
3.015e+38
0.2
5.833e+38
0.4
37
Bu
306
310
310
310
38
Bg
310
314
312
342
3.569e+38
0.2
3.802e+38
0.2
7.371e+38
0.5
39
Bg
362
362
362
362
3.226e+37
0.0
3.406e+37
0.0
6.632e+37
0.0
40
Bu
376
377
377
377
41
Ag
377
379
378
381
7.042e+38
0.4
6.136e+38
0.4
1.318e+39
0.8
42
Au
381
419
416
399
43
Bu
428
428
428
428
44
Bg
436
436
436
436
1.559e+39
1.0
1.174e+39
0.7
2.733e+39
1.7
45
Au
452
452
452
452
46
Ag
461
461
461
461
6.231e+39
3.9
8.327e+39
5.2
1.456e+40
9.0
47
Bg
463
463
463
463
3.167e+39
2.0
3.314e+39
2.1
6.481e+39
4.0
48
Ag
470
470
470
470
4.413e+39
2.7
5.157e+39
3.2
9.571e+39
5.9
49
Bu
471
472
472
472
50
Au
478
478
478
478
51
Au
597
598
599
597
52
Bu
601
602
602
602
53
Ag
602
607
606
602
4.198e+39
2.6
4.749e+39
2.9
8.946e+39
5.5
54
Bg
611
611
611
611
1.292e+39
0.8
1.412e+39
0.9
2.705e+39
1.7
55
Au
620
622
622
620
56
Bg
623
623
623
623
2.580e+39
1.6
2.003e+39
1.2
4.583e+39
2.8
57
Bu
624
625
625
625
58
Ag
625
629
629
627
6.435e+39
4.0
8.129e+39
5.0
1.456e+40
9.0
59
Bu
631
631
631
633
60
Ag
633
633
633
635
3.870e+39
2.4
1.543e+39
1.0
5.413e+39
3.4
61
Au
635
636
637
639
62
Bg
652
652
652
652
2.589e+39
1.6
2.833e+39
1.8
5.423e+39
3.4
63
Bg
1008
1008
1008
1008
8.864e+37
0.1
6.680e+37
0.0
1.554e+38
0.1
64
Au
1009
1009
1009
1009
65
Bu
1014
1014
1014
1014
66
Ag
1018
1018
1018
1018
1.615e+41
100.0
7.125e+36
0.0
1.615e+41
100.0
67
Ag
1103
1103
1103
1103
6.741e+39
4.2
8.545e+39
5.3
1.529e+40
9.5
68
Bu
1113
1113
1113
1114
69
Bu
1114
1117
1117
1117
70
Bg
1117
1126
1122
1134
5.198e+38
0.3
5.402e+38
0.3
1.060e+39
0.7
71
Au
1134
1145
1144
1146
72
Ag
1146
1146
1146
1147
4.528e+39
2.8
7.591e+39
4.7
1.212e+40
7.5
73
Au
1147
1170
1170
1169
74
Bu
1170
1171
1171
1171
75
Ag
1171
1173
1173
1173
5.026e+39
3.1
4.216e+39
2.6
9.242e+39
5.7
76
Bg
1173
1186
1186
1186
2.998e+39
1.9
2.363e+39
1.5
5.361e+39
3.3
77
Bg
1186
1199
1198
1200
6.338e+39
3.9
6.814e+39
4.2
1.315e+40
8.1
78
Au
1200
1225
1229
1220
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.