-    NATRITE     -    Na2CO3

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:  12  C2/m 
Lattice parameters (Å):  8.9050  5.2370  6.0450 
Angles (°):  90  101.32  90 

Symmetry (theoretical): 

Space group:  12  C2/m 
Lattice parameters (Å):  5.0163  5.0163  5.7629 
Angles (°):  78.14  101.85  117.90 

Cell contents: 

Number of atoms:  12 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Na:  0.0000  0.0000  0.0000 
Na:  0.0000  0.0000  0.5000 
Na:  0.6682  0.3318  0.7374 
C:  0.6643  0.3357  0.2496 
O:  0.3886  0.1850  0.2941 
O:  0.7883  0.2117  0.1644 
Na:  0.3318  0.6682  0.2626 
C:  0.3357  0.6643  0.7504 
O:  0.1850  0.3886  0.7059 
O:  0.2117  0.7883  0.8356 
O:  0.6114  0.8150  0.7059 
O:  0.8150  0.6114  0.2941 
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
Au
-73
-73
-72
-73
2
Bg
-42
-42
-42
-42
3
Ac
0
0
0
0
4
Ac
0
0
0
0
5
Ac
0
0
0
0
6
Au
124
124
127
124
7
Bg
127
127
128
127
1.787e+39
2.2
2.100e+39
2.6
3.886e+39
4.8
8
Au
139
139
144
139
9
Ag
144
144
147
144
9.105e+38
1.1
1.023e+39
1.3
1.934e+39
2.4
10
Bu
147
148
153
153
11
Bg
153
153
160
160
2.847e+39
3.5
3.024e+39
3.8
5.871e+39
7.3
12
Ag
160
160
173
173
1.712e+39
2.1
1.083e+39
1.3
2.795e+39
3.5
13
Bu
173
185
182
177
14
Ag
187
187
187
187
3.399e+38
0.4
2.014e+38
0.3
5.413e+38
0.7
15
Bu
189
204
189
189
16
Bg
204
209
204
204
7.893e+39
9.8
1.026e+40
12.8
1.815e+40
22.6
17
Ag
234
234
234
234
6.203e+39
7.7
6.463e+39
8.0
1.267e+40
15.8
18
Ag
243
243
243
243
1.145e+39
1.4
8.608e+38
1.1
2.006e+39
2.5
19
Bu
246
246
246
257
20
Au
258
258
261
258
21
Bu
261
276
261
264
22
Bu
281
284
281
284
23
Au
284
307
312
312
24
Bu
312
341
340
350
25
Au
687
687
688
687
26
Bg
688
688
688
688
1.031e+39
1.3
1.731e+39
2.2
2.762e+39
3.4
27
Bu
697
698
697
698
28
Ag
698
698
698
698
9.707e+38
1.2
7.991e+38
1.0
1.770e+39
2.2
29
Bu
859
860
859
868
30
Ag
868
868
868
868
1.416e+38
0.2
1.584e+38
0.2
3.000e+38
0.4
31
Ag
1104
1104
1104
1104
7.693e+40
95.8
3.404e+39
4.2
8.033e+40
100.0
32
Bu
1104
1104
1104
1104
33
Bg
1441
1441
1441
1441
1.571e+39
2.0
2.641e+39
3.3
4.211e+39
5.2
34
Au
1451
1451
1457
1451
35
Bu
1457
1469
1469
1469
36
Ag
1469
1566
1572
1483
1.588e+39
2.0
1.733e+39
2.2
3.320e+39
4.1
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.