-    ARAGONITE     -    CaCO3

Theoretical atomic positions and lattice parameters at experimental volum from RRUFF entry #R060195 

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):  2.6251  4.2169  3.0381 
Angles (°):  90.0  90.0  90.0 

Symmetry (theoretical): 

Space group:  62  Pnma 
Lattice parameters (Å):  6.7203  5.8624  5.7607 
Angles (°):  90.0  90.0  90.0 

Cell contents: 

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

Atomic positions (theoretical):

Ca:  0.2500  0.3130  0.0214 
C:  0.2500  0.7831  0.0141 
O:  0.2500  0.9430  0.8672 
O:  0.4107  0.6973  0.0980 
Ca:  0.7500  0.1870  0.5214 
C:  0.7500  0.7169  0.5141 
O:  0.7500  0.5570  0.3672 
O:  0.5893  0.8027  0.5980 
Ca:  0.7500  0.6870  0.9786 
C:  0.7500  0.2169  0.9859 
O:  0.7500  0.0570  0.1328 
O:  0.9107  0.3027  0.9020 
Ca:  0.2500  0.8130  0.4786 
C:  0.2500  0.2831  0.4859 
O:  0.2500  0.4430  0.6328 
O:  0.0893  0.1973  0.4020 
O:  0.5893  0.3027  0.9020 
O:  0.4107  0.1973  0.4020 
O:  0.0893  0.6973  0.0980 
O:  0.9107  0.8027  0.5980 
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
Au
92
92
92
92
5
B2g
98
98
98
98
4.155e+37
0.0
5.713e+37
0.0
9.869e+37
0.1
6
A1g
102
102
102
102
7.627e+38
0.6
1.831e+38
0.2
9.458e+38
0.8
7
B1u
117
117
117
117
8
B3g
119
119
119
119
3.217e+38
0.3
4.424e+38
0.4
7.642e+38
0.6
9
Au
122
122
122
122
10
B2g
123
123
123
123
2.267e+38
0.2
3.118e+38
0.3
5.385e+38
0.5
11
B1g
130
130
130
130
8.729e+38
0.7
1.200e+39
1.0
2.073e+39
1.7
12
A1g
134
134
134
134
7.286e+38
0.6
1.401e+38
0.1
8.687e+38
0.7
13
B3u
135
160
135
135
14
B3u
164
166
164
164
15
B1g
168
168
168
168
3.386e+39
2.8
4.655e+39
3.9
8.041e+39
6.7
16
B3g
178
178
178
178
7.140e+38
0.6
9.817e+38
0.8
1.696e+39
1.4
17
B1g
181
181
181
181
5.748e+39
4.8
7.903e+39
6.6
1.365e+40
11.5
18
Au
183
183
183
183
19
B2u
189
189
194
189
20
B2u
213
213
222
213
21
B2g
222
222
228
222
3.949e+39
3.3
5.430e+39
4.6
9.379e+39
7.9
22
A1g
228
228
235
228
1.599e+40
13.4
1.199e+40
10.1
2.798e+40
23.5
23
B1u
252
252
252
259
24
B3g
271
271
271
271
1.373e+37
0.0
1.888e+37
0.0
3.260e+37
0.0
25
B1u
271
271
271
274
26
B2u
274
274
276
276
27
B3g
276
276
279
279
4.484e+37
0.0
6.165e+37
0.1
1.065e+38
0.1
28
A1g
279
279
297
297
1.288e+39
1.1
9.534e+38
0.8
2.241e+39
1.9
29
Au
297
297
304
304
30
B1g
304
304
304
304
5.957e+38
0.5
8.190e+38
0.7
1.415e+39
1.2
31
B2g
304
304
308
308
1.544e+39
1.3
2.123e+39
1.8
3.668e+39
3.1
32
B3u
308
365
312
330
33
B2u
365
367
367
365
34
A1g
367
368
389
367
1.279e+40
10.7
9.575e+39
8.0
2.237e+40
18.8
35
B1u
389
389
389
389
1.416e+36
0.0
1.947e+36
0.0
3.362e+36
0.0
36
B3g
389
389
419
435
5.485e+37
0.0
7.542e+37
0.1
1.303e+38
0.1
37
Au
636
636
636
636
38
B1g
643
643
643
643
1.249e+39
1.0
1.718e+39
1.4
2.967e+39
2.5
39
B3u
644
645
644
644
40
B2g
656
656
656
656
1.777e+39
1.5
2.443e+39
2.0
4.219e+39
3.5
41
A1g
741
741
741
741
1.768e+39
1.5
1.258e+39
1.1
3.026e+39
2.5
42
B1u
743
743
743
745
43
B3g
746
746
746
746
4.745e+37
0.0
6.524e+37
0.1
1.127e+38
0.1
44
B2u
747
747
748
747
45
B1u
883
883
883
883
6.148e+36
0.0
9.195e+35
0.0
7.067e+36
0.0
46
B1g
883
883
883
883
1.642e+38
0.1
3.797e+37
0.0
2.022e+38
0.2
47
B2u
883
883
883
883
48
B3g
883
883
890
890
1.108e+37
0.0
1.523e+37
0.0
2.631e+37
0.0
49
B1u
1094
1094
1094
1094
50
B2u
1094
1094
1094
1094
51
B3g
1096
1096
1096
1096
2.081e+39
1.7
2.861e+39
2.4
4.942e+39
4.1
52
A1g
1097
1097
1097
1097
1.170e+41
98.2
2.173e+39
1.8
1.192e+41
100.0
53
B3u
1366
1379
1366
1366
54
B2g
1379
1383
1379
1379
3.136e+38
0.3
4.311e+38
0.4
7.447e+38
0.6
55
Au
1383
1464
1383
1383
56
B1g
1464
1494
1464
1464
2.236e+39
1.9
3.074e+39
2.6
5.310e+39
4.5
57
A1g
1494
1494
1494
1494
9.103e+39
7.6
6.584e+39
5.5
1.569e+40
13.2
58
B1u
1513
1513
1513
1527
59
B3g
1527
1527
1527
1536
6.969e+38
0.6
9.582e+38
0.8
1.655e+39
1.4
60
B2u
1536
1536
1609
1576
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.