-    HUNTITE     -    Mg3Ca(CO3)4

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:  155  R32 
Lattice parameters (Å):  9.5027  9.5027  7.8212 
Angles (°):  90.0  90.0  120.0 

Symmetry (theoretical): 

Space group:  155  R32 
Lattice parameters (Å):  6.0757  6.0757  6.0757 
Angles (°):  103.0  103.0  103.0 

Cell contents: 

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

Atomic positions (theoretical):

Ca:  0.0000  0.0000  0.0000 
Mg:  0.5438  0.4562  0.0000 
C:  0.5000  0.5000  0.5000 
C:  0.9556  0.0444  0.5000 
O:  0.3652  0.6348  0.5000 
O:  0.0910  0.9090  0.5000 
O:  0.9753  0.1940  0.3832 
Mg:  0.4562  0.0000  0.5438 
C:  0.0444  0.5000  0.9556 
O:  0.6348  0.5000  0.3652 
O:  0.9090  0.5000  0.0910 
O:  0.1940  0.3832  0.9753 
Mg:  0.0000  0.5438  0.4562 
C:  0.5000  0.9556  0.0444 
O:  0.5000  0.3652  0.6348 
O:  0.5000  0.0910  0.9090 
O:  0.6168  0.8060  0.0247 
O:  0.3832  0.9753  0.1940 
O:  0.8060  0.0247  0.6168 
O:  0.0247  0.6168  0.8060 
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
A2
74
74
74
90
5
E
113
113
113
113
1.733e+39
2.0
2.297e+39
2.7
4.030e+39
4.7
6
E
113
120
120
113
1.733e+39
2.0
2.675e+39
3.1
4.408e+39
5.2
7
E
152
152
152
152
8.186e+38
1.0
1.065e+39
1.2
1.883e+39
2.2
8
E
152
152
152
152
8.186e+38
1.0
1.291e+39
1.5
2.110e+39
2.5
9
A2
163
163
163
163
10
A1
165
165
165
165
2.989e+38
0.3
1.849e+38
0.2
4.838e+38
0.6
11
E
174
174
174
174
1.000e+38
0.1
1.363e+38
0.2
2.363e+38
0.3
12
E
174
174
174
174
1.000e+38
0.1
1.289e+38
0.2
2.289e+38
0.3
13
A2
183
183
183
184
14
A2
209
209
209
228
15
E
228
228
228
228
1.123e+39
1.3
1.404e+39
1.6
2.527e+39
3.0
16
E
228
230
230
228
1.123e+39
1.3
1.264e+39
1.5
2.387e+39
2.8
17
E
240
240
240
240
5.634e+39
6.6
7.425e+39
8.7
1.306e+40
15.3
18
E
240
248
248
240
5.634e+39
6.6
8.760e+39
10.2
1.439e+40
16.8
19
A2
254
254
254
257
20
E
267
267
267
267
2.849e+39
3.3
3.476e+39
4.1
6.325e+39
7.4
21
E
267
268
268
267
2.849e+39
3.3
4.686e+39
5.5
7.535e+39
8.8
22
E
274
274
274
274
1.076e+39
1.3
8.987e+38
1.1
1.975e+39
2.3
23
E
274
285
285
274
1.076e+39
1.3
1.250e+39
1.5
2.326e+39
2.7
24
A2
293
293
293
295
25
A1
297
297
297
297
1.587e+38
0.2
1.412e+37
0.0
1.728e+38
0.2
26
E
314
314
314
314
3.516e+39
4.1
4.413e+39
5.2
7.930e+39
9.3
27
E
314
314
314
314
3.516e+39
4.1
3.970e+39
4.6
7.486e+39
8.8
28
A2
316
316
316
327
29
E
337
337
337
337
1.754e+38
0.2
2.338e+38
0.3
4.092e+38
0.5
30
E
337
347
347
337
1.754e+38
0.2
2.138e+38
0.3
3.892e+38
0.5
31
E
355
355
355
355
2.288e+38
0.3
1.851e+38
0.2
4.139e+38
0.5
32
E
355
355
355
355
2.288e+38
0.3
2.728e+38
0.3
5.016e+38
0.6
33
A2
355
367
367
376
34
E
376
376
376
376
1.569e+39
1.8
1.962e+39
2.3
3.531e+39
4.1
35
E
376
388
388
388
1.569e+39
1.8
1.766e+39
2.1
3.335e+39
3.9
36
A1
388
459
459
440
3.151e+38
0.4
2.073e+38
0.2
5.225e+38
0.6
37
E
686
686
686
686
2.361e+38
0.3
1.776e+38
0.2
4.137e+38
0.5
38
E
686
687
687
686
2.361e+38
0.3
3.162e+38
0.4
5.524e+38
0.6
39
A1
703
703
703
703
5.630e+37
0.1
4.160e+37
0.0
9.789e+37
0.1
40
E
706
706
706
706
1.321e+39
1.5
1.023e+39
1.2
2.343e+39
2.7
41
E
706
706
706
706
1.321e+39
1.5
1.976e+39
2.3
3.296e+39
3.9
42
A2
713
713
713
713
43
E
726
726
726
726
6.670e+38
0.8
5.067e+38
0.6
1.174e+39
1.4
44
E
726
727
727
726
6.670e+38
0.8
8.658e+38
1.0
1.533e+39
1.8
45
A2
838
838
838
853
46
E
854
854
854
854
1.574e+39
1.8
1.884e+39
2.2
3.458e+39
4.0
47
E
854
855
855
854
1.574e+39
1.8
2.609e+39
3.1
4.183e+39
4.9
48
A2
865
865
865
877
49
A1
1092
1092
1092
1092
2.430e+37
0.0
1.601e+37
0.0
4.031e+37
0.0
50
E
1100
1100
1100
1100
9.454e+37
0.1
1.026e+38
0.1
1.971e+38
0.2
51
E
1100
1100
1100
1100
9.454e+37
0.1
1.005e+38
0.1
1.951e+38
0.2
52
A1
1108
1108
1108
1108
8.336e+40
97.5
2.145e+39
2.5
8.550e+40
100.0
53
E
1424
1424
1424
1424
3.771e+38
0.4
2.950e+38
0.3
6.721e+38
0.8
54
E
1424
1444
1444
1424
3.771e+38
0.4
5.708e+38
0.7
9.478e+38
1.1
55
E
1446
1446
1446
1446
1.231e+39
1.4
9.233e+38
1.1
2.154e+39
2.5
56
E
1446
1460
1460
1446
1.231e+39
1.4
1.693e+39
2.0
2.924e+39
3.4
57
A1
1460
1476
1476
1460
1.306e+38
0.2
4.803e+37
0.1
1.786e+38
0.2
58
A2
1484
1484
1484
1486
59
E
1497
1497
1497
1497
1.565e+37
0.0
2.152e+37
0.0
3.717e+37
0.0
60
E
1497
1595
1595
1497
1.565e+37
0.0
2.152e+37
0.0
3.717e+37
0.0
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.