-    BARYTOCALCITE     -    BaCa(CO3)2

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:  4  P2_1 
Lattice parameters (Å):  8.1500  5.2200  6.5800 
Angles (°):  90  106.13  90 

Symmetry (theoretical): 

Space group:  4  P2_1 
Lattice parameters (Å):  7.9701  5.1936  6.4574 
Angles (°):  90  106.34  90 

Cell contents: 

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

Atomic positions (theoretical):

Ba:  0.1471  0.2247  0.2896 
Ca:  0.3764  0.7247  0.8047 
C:  0.0957  0.2247  0.7512 
C:  0.3817  0.7247  0.2513 
O:  0.9863  0.2247  0.8610 
O:  0.1482  0.4370  0.6900 
O:  0.1483  0.0124  0.6900 
O:  0.3616  0.7247  0.4372 
O:  0.3894  0.9362  0.1499 
O:  0.3894  0.5132  0.1498 
Ba:  0.8529  0.7247  0.7104 
Ca:  0.6236  0.2247  0.1953 
C:  0.9043  0.7247  0.2488 
C:  0.6183  0.2247  0.7487 
O:  0.0137  0.7247  0.1390 
O:  0.8518  0.9370  0.3100 
O:  0.8517  0.5124  0.3100 
O:  0.6384  0.2247  0.5628 
O:  0.6106  0.4362  0.8501 
O:  0.6106  0.0132  0.8502 
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
3.941e+39
6.4
2.911e+39
4.7
6.852e+39
11.1
5
A
73
73
73
73
7.911e+38
1.3
1.212e+39
2.0
2.003e+39
3.2
6
B
80
80
87
80
7
B
89
89
89
89
1.805e+39
2.9
1.276e+39
2.1
3.081e+39
5.0
8
A
93
93
93
93
7.696e+39
12.4
1.141e+40
18.4
1.910e+40
30.8
9
A
94
101
94
96
10
A
121
123
121
121
11
B
123
130
130
123
12
A
130
132
132
130
6.678e+39
10.8
8.095e+39
13.1
1.477e+40
23.8
13
B
132
138
136
132
3.562e+39
5.7
2.274e+39
3.7
5.836e+39
9.4
14
B
138
139
142
138
15
A
153
155
153
155
16
B
156
156
156
156
2.959e+39
4.8
3.956e+39
6.4
6.915e+39
11.2
17
B
159
159
167
159
18
A
167
167
167
167
2.566e+39
4.1
2.935e+39
4.7
5.501e+39
8.9
19
B
169
169
169
169
3.447e+39
5.6
1.702e+39
2.7
5.149e+39
8.3
20
A
186
195
186
199
21
A
199
199
199
199
7.879e+38
1.3
1.221e+39
2.0
2.009e+39
3.2
22
B
199
199
208
208
23
A
208
208
210
210
2.941e+39
4.7
3.124e+39
5.0
6.065e+39
9.8
24
B
210
210
218
214
7.528e+39
12.1
5.695e+39
9.2
1.322e+40
21.3
25
B
233
233
233
233
1.119e+40
18.1
8.437e+39
13.6
1.962e+40
31.7
26
A
243
246
243
245
27
B
247
247
251
247
28
A
266
267
266
267
29
B
273
273
273
273
4.610e+39
7.4
3.262e+39
5.3
7.872e+39
12.7
30
A
293
293
293
293
1.261e+40
20.3
1.554e+40
25.1
2.815e+40
45.4
31
A
299
299
299
312
32
B
312
312
312
330
2.006e+39
3.2
7.372e+38
1.2
2.743e+39
4.4
33
A
330
330
330
332
7.360e+38
1.2
8.591e+38
1.4
1.595e+39
2.6
34
A
335
336
335
336
35
B
336
345
345
345
36
B
345
396
382
368
2.699e+39
4.4
2.821e+39
4.6
5.520e+39
8.9
37
B
671
671
671
671
38
A
679
679
679
679
1.297e+39
2.1
2.184e+39
3.5
3.481e+39
5.6
39
B
683
683
683
683
2.400e+39
3.9
2.029e+39
3.3
4.429e+39
7.1
40
A
688
689
688
689
41
B
693
693
693
693
42
A
693
693
694
693
1.621e+39
2.6
2.336e+39
3.8
3.956e+39
6.4
43
B
716
716
716
716
1.514e+39
2.4
1.127e+39
1.8
2.641e+39
4.3
44
A
723
723
723
723
45
A
841
843
841
842
46
B
843
848
843
843
1.487e+38
0.2
4.951e+37
0.1
1.982e+38
0.3
47
B
858
858
858
858
9.459e+38
1.5
8.807e+37
0.1
1.034e+39
1.7
48
A
858
859
858
862
49
A
1095
1096
1095
1095
50
B
1097
1097
1097
1097
6.024e+39
9.7
1.600e+38
0.3
6.184e+39
10.0
51
A
1099
1100
1099
1099
52
B
1100
1100
1100
1100
5.996e+40
96.8
2.001e+39
3.2
6.196e+40
100.0
53
B
1365
1365
1391
1365
54
A
1391
1391
1391
1391
3.870e+38
0.6
4.182e+38
0.7
8.052e+38
1.3
55
B
1408
1408
1439
1408
56
A
1439
1439
1468
1439
1.530e+39
2.5
1.907e+39
3.1
3.437e+39
5.5
57
A
1468
1495
1495
1492
58
B
1495
1511
1509
1495
6.132e+38
1.0
3.338e+38
0.5
9.470e+38
1.5
59
A
1534
1538
1534
1538
60
B
1538
1541
1538
1582
4.697e+39
7.6
1.596e+39
2.6
6.293e+39
10.2
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.