-    ALSTONITE     -    BaCa(CO3)2

Theoretical atomic positions and lattice parameters at experimental volum from ICSD database, code 24442 

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:  4  P2_1 
Lattice parameters (Å):  5.0492  5.0492  17.3430 
Angles (°):  90  105.56  90 

Symmetry (theoretical): 

Space group:  4  P2_1 
Lattice parameters (Å):  8.1804  5.2181  6.5341 
Angles (°):  47.15  47.15  47.15 

Cell contents: 

Number of atoms:  20 
Number of atom types:  4 
Chemical composition:  0 

Atomic positions (theoretical):

Ca:  0.1226  1.0000  0.1984 
Ba:  0.6420  0.0001  0.2852 
C:  0.1199  0.9999  0.7504 
C:  0.6003  0.0001  0.7500 
O:  0.1095  0.2109  0.8496 
O:  0.1454  0.9999  0.5690 
O:  0.1095  0.7889  0.8495 
O:  0.6515  0.7880  0.6892 
O:  0.6514  0.2120  0.6890 
O:  0.4935  0.0001  0.8600 
Ca:  0.8774  0.5000  0.8016 
Ba:  0.3580  0.5001  0.7148 
C:  0.8801  0.4999  0.2496 
C:  0.3997  0.5001  0.2500 
O:  0.8905  0.7109  0.1504 
O:  0.8546  0.4999  0.4310 
O:  0.8905  0.2889  0.1505 
O:  0.3485  0.2880  0.3108 
O:  0.3486  0.7120  0.3110 
O:  0.5065  0.5001  0.1400 
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
B
71
71
71
71
1.163e+38
0.2
1.600e+38
0.3
2.763e+38
0.5
5
A
72
72
73
72
6
A
73
73
82
73
3.434e+39
6.6
2.477e+39
4.7
5.911e+39
11.3
7
A
85
85
85
85
1.416e+39
2.7
1.221e+39
2.3
2.636e+39
5.0
8
B
86
86
86
86
7.332e+39
14.0
1.105e+40
21.1
1.838e+40
35.1
9
B
90
96
90
93
10
A
113
113
114
113
11
B
114
114
116
114
7.204e+39
13.8
9.103e+39
17.4
1.631e+40
31.2
12
B
116
127
123
116
13
A
127
127
127
127
1.189e+38
0.2
9.018e+37
0.2
2.091e+38
0.4
14
A
127
137
134
127
4.495e+39
8.6
3.403e+39
6.5
7.898e+39
15.1
15
B
142
142
142
142
16
A
142
143
143
143
17
A
149
149
149
149
2.807e+39
5.4
3.430e+39
6.6
6.236e+39
11.9
18
B
156
156
156
156
2.846e+39
5.4
3.231e+39
6.2
6.077e+39
11.6
19
A
163
163
163
163
2.138e+39
4.1
8.451e+38
1.6
2.983e+39
5.7
20
B
169
169
169
169
1.518e+39
2.9
1.733e+39
3.3
3.251e+39
6.2
21
B
175
183
175
188
22
A
188
188
194
194
23
A
194
194
195
195
7.145e+39
13.7
5.810e+39
11.1
1.295e+40
24.8
24
B
195
195
208
201
1.517e+39
2.9
1.805e+39
3.4
3.321e+39
6.3
25
A
217
217
217
217
1.050e+40
20.1
7.858e+39
15.0
1.836e+40
35.1
26
A
225
225
226
225
27
B
226
231
229
227
28
A
245
245
245
245
4.560e+39
8.7
3.361e+39
6.4
7.921e+39
15.1
29
B
250
251
250
251
30
B
264
264
264
269
4.332e+36
0.0
5.956e+36
0.0
1.029e+37
0.0
31
B
269
269
269
278
1.249e+40
23.9
1.528e+40
29.2
2.778e+40
53.1
32
A
278
278
278
299
4.880e+39
9.3
2.182e+39
4.2
7.062e+39
13.5
33
B
299
299
299
302
8.243e+38
1.6
8.885e+38
1.7
1.713e+39
3.3
34
A
302
302
310
309
5.742e+35
0.0
1.914e+35
0.0
7.655e+35
0.0
35
B
310
318
318
318
36
A
318
373
353
339
3.146e+39
6.0
3.138e+39
6.0
6.284e+39
12.0
37
A
667
667
668
667
38
B
674
674
674
674
9.839e+38
1.9
1.660e+39
3.2
2.644e+39
5.1
39
A
677
677
677
677
2.280e+39
4.4
1.947e+39
3.7
4.227e+39
8.1
40
B
681
682
681
682
41
A
688
688
688
688
1.318e+39
2.5
1.886e+39
3.6
3.204e+39
6.1
42
B
688
688
689
688
43
A
704
704
704
704
1.498e+39
2.9
1.085e+39
2.1
2.583e+39
4.9
44
B
709
709
709
710
45
B
845
847
845
846
46
A
847
851
847
847
1.379e+38
0.3
1.345e+37
0.0
1.513e+38
0.3
47
A
859
859
859
859
5.568e+38
1.1
8.740e+37
0.2
6.442e+38
1.2
48
B
859
860
859
862
49
B
1082
1083
1082
1082
50
A
1084
1084
1084
1084
1.156e+40
22.1
3.492e+38
0.7
1.191e+40
22.8
51
B
1088
1088
1088
1088
52
A
1088
1088
1088
1088
5.055e+40
96.6
1.775e+39
3.4
5.232e+40
100.0
53
A
1349
1349
1376
1349
54
B
1376
1376
1376
1376
4.101e+38
0.8
4.666e+38
0.9
8.768e+38
1.7
55
A
1396
1396
1424
1396
56
B
1424
1424
1453
1424
1.697e+39
3.2
2.187e+39
4.2
3.884e+39
7.4
57
B
1453
1479
1479
1479
58
A
1479
1496
1494
1479
6.548e+38
1.3
4.068e+38
0.8
1.062e+39
2.0
59
B
1517
1520
1517
1520
60
A
1520
1525
1520
1562
6.392e+39
12.2
2.192e+39
4.2
8.584e+39
16.4
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.