-    SHORTITE     -    Ca2Na2(CO3)3

Theoretical atomic positions and lattice parameters at experimental volum from 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):  2.6178  5.8379  3.7614 
Angles (°):  90.0  90.0  90.0 

Symmetry (theoretical): 

Space group:  38  Amm2 
Lattice parameters (Å):  4.9422  6.5592  6.5592 
Angles (°):    114.2  90.0 

Cell contents: 

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

Atomic positions (theoretical):

Ca:  0.5000  0.2136  0.7802 
Na:  0.0000  0.9202  0.9202 
Na:  0.5000  0.6129  0.6129 
C:  0.0000  0.4666  0.8719 
O:  0.0000  0.2720  0.8705 
O:  0.2257  0.5625  0.8694 
C:  0.5000  0.2268  0.2268 
O:  0.5000  0.0442  0.0442 
O:  0.5000  0.4139  0.2116 
Ca:  0.5000  0.7802  0.2136 
C:  0.0000  0.8719  0.4666 
O:  0.0000  0.8705  0.2720 
O:  0.7743  0.8694  0.5625 
O:  0.5000  0.2116  0.4139 
O:  0.2257  0.8694  0.5625 
O:  0.7743  0.5625  0.8694 
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
95
112
95
95
3.009e+38
0.6
4.137e+38
0.8
7.146e+38
1.5
5
A2
120
120
120
120
3.905e+38
0.8
5.370e+38
1.1
9.275e+38
1.9
6
B1/B2
134
134
135
134
8.002e+38
1.6
1.100e+39
2.3
1.901e+39
3.9
7
A1
138
138
138
139
1.905e+39
3.9
2.213e+37
0.0
1.928e+39
4.0
8
A1
145
145
145
146
2.709e+39
5.6
1.801e+39
3.7
4.510e+39
9.3
9
B1/B2
150
152
150
150
9.506e+38
2.0
1.307e+39
2.7
2.258e+39
4.6
10
B1/B2
165
165
169
165
1.154e+38
0.2
1.587e+38
0.3
2.741e+38
0.6
11
A2
169
169
171
169
3.440e+37
0.1
4.730e+37
0.1
8.170e+37
0.2
12
B1/B2
171
173
173
171
1.324e+37
0.0
1.821e+37
0.0
3.146e+37
0.1
13
A2
173
173
173
173
1.822e+39
3.7
2.505e+39
5.1
4.327e+39
8.9
14
B1/B2
177
177
177
177
2.729e+39
5.6
3.753e+39
7.7
6.482e+39
13.3
15
A1
183
183
183
183
6.163e+38
1.3
4.564e+38
0.9
1.073e+39
2.2
16
B1/B2
184
184
187
184
17
A1
187
187
189
188
5.233e+38
1.1
3.333e+38
0.7
8.566e+38
1.8
18
B1/B2
200
200
203
200
3.649e+38
0.7
5.017e+38
1.0
8.665e+38
1.8
19
B1/B2
203
204
208
203
3.464e+38
0.7
4.763e+38
1.0
8.227e+38
1.7
20
A1
210
210
210
210
2.673e+39
5.5
1.138e+39
2.3
3.811e+39
7.8
21
A2
210
210
210
242
2.529e+39
5.2
3.477e+39
7.1
6.006e+39
12.3
22
B1/B2
242
242
242
244
5.689e+38
1.2
7.822e+38
1.6
1.351e+39
2.8
23
B1/B2
244
245
244
245
1.032e+39
2.1
1.419e+39
2.9
2.450e+39
5.0
24
B1/B2
245
254
254
245
1.609e+38
0.3
2.212e+38
0.5
3.820e+38
0.8
25
A1
254
254
259
259
4.348e+38
0.9
1.139e+38
0.2
5.487e+38
1.1
26
B1/B2
259
264
262
264
7.475e+39
15.4
1.028e+40
21.1
1.775e+40
36.5
27
A2
264
266
264
265
9.906e+38
2.0
1.362e+39
2.8
2.353e+39
4.8
28
A1
266
285
266
285
7.442e+39
15.3
5.183e+39
10.6
1.263e+40
25.9
29
B1/B2
285
336
294
336
30
B1/B2
336
359
387
336
1.619e+38
0.3
2.226e+38
0.5
3.845e+38
0.8
31
B1/B2
680
680
681
680
2.507e+37
0.1
3.447e+37
0.1
5.954e+37
0.1
32
A1
681
681
681
681
5.656e+38
1.2
3.973e+38
0.8
9.629e+38
2.0
33
A1
694
694
694
695
7.840e+38
1.6
5.701e+38
1.2
1.354e+39
2.8
34
A2
703
703
703
703
7.009e+38
1.4
9.637e+38
2.0
1.665e+39
3.4
35
B1/B2
705
707
705
705
5.734e+38
1.2
7.884e+38
1.6
1.362e+39
2.8
36
B1/B2
727
727
728
727
8.192e+38
1.7
1.126e+39
2.3
1.945e+39
4.0
37
B1/B2
834
836
834
834
1.770e+37
0.0
2.433e+37
0.0
4.203e+37
0.1
38
A1
846
846
846
852
1.320e+39
2.7
2.019e+38
0.4
1.521e+39
3.1
39
B1/B2
852
852
856
852
40
A1
1077
1077
1077
1078
8.661e+39
17.8
7.443e+38
1.5
9.405e+39
19.3
41
B1/B2
1084
1084
1085
1084
5.932e+38
1.2
8.157e+38
1.7
1.409e+39
2.9
42
A1
1085
1085
1085
1085
4.866e+40
100.0
1.826e+37
0.0
4.868e+40
100.0
43
A1
1409
1409
1409
1413
1.479e+39
3.0
6.098e+37
0.1
1.540e+39
3.2
44
A2
1413
1413
1413
1424
6.592e+36
0.0
9.063e+36
0.0
1.566e+37
0.0
45
B1/B2
1432
1466
1432
1432
5.124e+38
1.1
7.045e+38
1.4
1.217e+39
2.5
46
A1
1466
1487
1466
1487
1.538e+39
3.2
2.318e+38
0.5
1.769e+39
3.6
47
B1/B2
1487
1515
1515
1515
6.293e+38
1.3
8.653e+38
1.8
1.495e+39
3.1
48
B1/B2
1515
1524
1586
1518
2.448e+39
5.0
3.366e+39
6.9
5.813e+39
11.9
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.