-    SHORTITE     -    Ca2Na2(CO3)3

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:  38  Amm2 
Lattice parameters (Å):  4.9470  11.0320  7.1080 
Angles (°):  90  90  90 

Symmetry (theoretical): 

Space group:  38  Amm2 
Lattice parameters (Å):  4.8834  6.4532  6.4532 
Angles (°):  114.95  90  90 

Cell contents: 

Number of atoms:  16 
Number of atom types:  4 
Chemical composition:  0 

Atomic positions (theoretical):

Ca:  0.5000  0.2130  0.7804 
Na:  0.0000  0.9227  0.9227 
Na:  0.5000  0.6144  0.6144 
C:  0.0000  0.4661  0.8737 
O:  0.0000  0.2719  0.8801 
O:  0.2273  0.5619  0.8673 
C:  0.5000  0.2244  0.2244 
O:  0.5000  0.0375  0.0375 
O:  0.5000  0.4148  0.2107 
Ca:  0.5000  0.7804  0.2130 
C:  0.0000  0.8737  0.4661 
O:  0.0000  0.8801  0.2719 
O:  0.7727  0.8673  0.5619 
O:  0.5000  0.2107  0.4148 
O:  0.2273  0.8673  0.5619 
O:  0.7727  0.5619  0.8673 
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
B1/B2
119
130
119
119
9.724e+37
0.2
1.337e+38
0.2
2.309e+38
0.4
5
A2
130
135
130
130
1.417e+39
2.6
1.948e+39
3.6
3.365e+39
6.2
6
B1/B2
139
139
139
139
1.436e+39
2.6
1.974e+39
3.6
3.410e+39
6.3
7
B1/B2
150
153
150
150
6.948e+38
1.3
9.554e+38
1.8
1.650e+39
3.0
8
A1
153
154
153
157
2.130e+39
3.9
7.328e+38
1.3
2.863e+39
5.3
9
A1
160
160
160
160
1.376e+39
2.5
7.041e+38
1.3
2.080e+39
3.8
10
A2
177
177
177
177
6.088e+38
1.1
8.372e+38
1.5
1.446e+39
2.7
11
B1/B2
182
183
182
182
9.954e+37
0.2
1.369e+38
0.3
2.364e+38
0.4
12
B1/B2
184
184
184
184
3.875e+39
7.1
5.328e+39
9.8
9.203e+39
16.9
13
B1/B2
185
185
185
185
2.282e+37
0.0
3.138e+37
0.1
5.420e+37
0.1
14
A1
192
192
192
194
4.165e+38
0.8
2.905e+38
0.5
7.070e+38
1.3
15
B1/B2
196
196
197
196
16
A2
197
197
203
197
6.932e+38
1.3
9.531e+38
1.8
1.646e+39
3.0
17
A1
203
203
211
203
1.104e+39
2.0
7.143e+38
1.3
1.818e+39
3.3
18
A2
224
224
224
224
2.484e+39
4.6
3.416e+39
6.3
5.900e+39
10.9
19
B1/B2
225
226
225
225
2.955e+38
0.5
4.063e+38
0.7
7.018e+38
1.3
20
B1/B2
239
239
244
239
3.287e+38
0.6
4.520e+38
0.8
7.807e+38
1.4
21
A1
247
247
247
267
2.123e+39
3.9
6.828e+38
1.3
2.806e+39
5.2
22
B1/B2
267
267
269
271
5.732e+38
1.1
7.882e+38
1.5
1.361e+39
2.5
23
B1/B2
271
276
271
273
2.913e+39
5.4
4.006e+39
7.4
6.919e+39
12.7
24
B1/B2
283
283
285
283
25
B1/B2
285
286
286
285
4.727e+39
8.7
6.500e+39
12.0
1.123e+40
20.7
26
A2
286
287
287
286
4.605e+38
0.8
6.332e+38
1.2
1.094e+39
2.0
27
A1
287
293
293
292
5.919e+39
10.9
4.375e+39
8.1
1.029e+40
19.0
28
A1
293
311
293
311
1.450e+39
2.7
6.381e+38
1.2
2.088e+39
3.8
29
B1/B2
311
380
324
365
7.581e+35
0.0
1.042e+36
0.0
1.801e+36
0.0
30
B1/B2
382
382
426
382
1.430e+38
0.3
1.966e+38
0.4
3.396e+38
0.6
31
A1
692
692
692
692
7.552e+38
1.4
4.923e+38
0.9
1.247e+39
2.3
32
B1/B2
693
693
694
693
4.457e+37
0.1
6.128e+37
0.1
1.058e+38
0.2
33
A1
707
707
707
708
1.028e+39
1.9
7.031e+38
1.3
1.731e+39
3.2
34
A2
709
709
709
709
1.019e+39
1.9
1.401e+39
2.6
2.420e+39
4.5
35
B1/B2
712
713
712
712
6.969e+38
1.3
9.582e+38
1.8
1.655e+39
3.0
36
B1/B2
744
744
746
744
1.197e+39
2.2
1.646e+39
3.0
2.843e+39
5.2
37
B1/B2
832
835
832
832
1.848e+37
0.0
2.541e+37
0.0
4.388e+37
0.1
38
A1
844
844
844
852
1.814e+39
3.3
2.734e+38
0.5
2.087e+39
3.8
39
B1/B2
853
853
856
853
5.994e+35
0.0
8.242e+35
0.0
1.424e+36
0.0
40
A1
1094
1094
1094
1094
8.115e+39
14.9
8.624e+38
1.6
8.978e+39
16.5
41
B1/B2
1101
1101
1101
1101
6.565e+38
1.2
9.027e+38
1.7
1.559e+39
2.9
42
A1
1101
1101
1101
1101
5.430e+40
100.0
4.140e+36
0.0
5.431e+40
100.0
43
A1
1430
1430
1430
1439
1.407e+39
2.6
2.801e+37
0.1
1.435e+39
2.6
44
A2
1439
1439
1439
1445
3.154e+37
0.1
4.336e+37
0.1
7.490e+37
0.1
45
B1/B2
1457
1481
1457
1457
3.855e+38
0.7
5.300e+38
1.0
9.155e+38
1.7
46
A1
1481
1501
1481
1501
1.428e+39
2.6
2.499e+38
0.5
1.678e+39
3.1
47
B1/B2
1501
1536
1536
1532
4.577e+38
0.8
6.293e+38
1.2
1.087e+39
2.0
48
B1/B2
1536
1551
1606
1536
2.205e+39
4.1
3.032e+39
5.6
5.237e+39
9.6
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.