-    TETRAROOSEVELTITE     -    BiAsO4

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:  88  I4_1/a 
Lattice parameters (Å):  5.0800  5.0800  11.7000 
Angles (°):  90  90  90 

Symmetry (theoretical): 

Space group:  88  I4_1/a 
Lattice parameters (Å):  6.8476  6.8476  6.8476 
Angles (°):  136.35  136.35  63.43 

Cell contents: 

Number of atoms:  12 
Number of atom types: 
Chemical composition: 

Atomic positions (theoretical):

Bi:  0.5000  0.5000  0.0000 
As:  0.0000  0.0000  0.0000 
O:  0.2232  0.3260  0.3945 
O:  0.9315  0.8287  0.6055 
Bi:  0.2500  0.7500  0.5000 
As:  0.7500  0.2500  0.5000 
O:  0.0760  0.1815  0.6028 
O:  0.5787  0.4732  0.3972 
O:  0.5268  0.9240  0.1055 
O:  0.8185  0.4213  0.8945 
O:  0.6740  0.0685  0.8972 
O:  0.1713  0.7768  0.1028 
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
0
0
0
0
2
0
0
0
0
3
0
0
0
0
4
48
48
48
64
5
64
64
64
64
6.326e+39
0.4
8.161e+39
0.5
1.449e+40
0.9
6
64
64
64
87
6.327e+39
0.4
9.237e+39
0.6
1.556e+40
1.0
7
87
87
87
114
2.526e+40
1.6
3.144e+40
2.0
5.670e+40
3.5
8
114
114
114
114
9
114
141
141
141
10
141
158
158
146
1.206e+40
0.8
1.658e+40
1.0
2.864e+40
1.8
11
158
158
158
158
7.108e+39
0.4
1.119e+40
0.7
1.830e+40
1.1
12
158
165
165
158
7.108e+39
0.4
8.361e+39
0.5
1.547e+40
1.0
13
178
178
178
178
14
178
218
218
178
15
218
219
219
218
3.219e+40
2.0
9.553e+39
0.6
4.174e+40
2.6
16
246
246
246
246
17
253
253
253
253
9.874e+39
0.6
1.385e+40
0.9
2.372e+40
1.5
18
253
253
253
253
9.874e+39
0.6
1.331e+40
0.8
2.318e+40
1.4
19
272
272
272
312
20
328
328
328
328
2.043e+41
12.7
1.246e+41
7.8
3.290e+41
20.5
21
347
347
347
347
2.981e+40
1.9
3.571e+40
2.2
6.551e+40
4.1
22
349
349
349
349
23
349
386
386
349
24
386
386
386
386
6.567e+40
4.1
1.029e+41
6.4
1.686e+41
10.5
25
386
411
411
386
6.567e+40
4.1
7.771e+40
4.8
1.434e+41
8.9
26
411
412
412
425
27
425
425
425
429
28
429
429
429
464
8.687e+40
5.4
1.194e+41
7.4
2.062e+41
12.9
29
675
675
675
675
1.490e+41
9.3
2.021e+41
12.6
3.512e+41
21.9
30
691
691
691
693
31
693
693
693
693
32
693
706
706
706
33
706
706
706
706
8.603e+40
5.4
1.141e+41
7.1
2.002e+41
12.5
34
706
743
743
743
8.603e+40
5.4
1.225e+41
7.6
2.085e+41
13.0
35
743
750
750
750
36
750
812
812
771
1.602e+42
100.0
7.243e+38
0.0
1.603e+42
100.0
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.