-    MONTROYDITE     -    HgO

Theoretical atomic positions. Lattice parameters fixed as in RRUFFentry#R070235 

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):  6.6060  5.5020  3.5100 
Angles (°):  90.0  90.0  90.0 

Symmetry (theoretical): 

Space group:  62  Pnma 
Lattice parameters (Å):  6.6060  5.5020  3.5100 
Angles (°):  90.0  90.0  90.0 

Cell contents: 

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

Atomic positions (theoretical):

Hg:  0.1251  0.2500  0.2409 
O:  0.3734  0.2500  0.5869 
Hg:  0.3749  0.7500  0.7409 
O:  0.1266  0.7500  0.0869 
Hg:  0.8749  0.7500  0.7591 
O:  0.6266  0.7500  0.4131 
Hg:  0.6251  0.2500  0.2591 
O:  0.8734  0.2500  0.9131 
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
A1g
30
30
30
30
5
B2g
33
33
33
33
8.099e+39
0.1
1.023e+39
0.0
9.122e+39
0.1
6
B3u
38
38
38
38
7
A1g
53
56
53
53
8
Au
56
58
56
56
5.571e+39
0.1
4.144e+39
0.0
9.715e+39
0.1
9
B3g
63
63
63
63
2.876e+40
0.3
3.955e+40
0.4
6.832e+40
0.6
10
B1g
65
65
65
65
11
Au
76
76
76
76
3.239e+38
0.0
4.454e+38
0.0
7.694e+38
0.0
12
B3g
99
99
99
99
1.453e+41
1.3
1.998e+41
1.9
3.451e+41
3.2
13
B2g
132
132
142
132
14
B2u
142
142
144
142
1.889e+39
0.0
2.597e+39
0.0
4.485e+39
0.0
15
B1u
144
144
235
151
16
B1g
235
235
256
235
7.615e+39
0.1
1.047e+40
0.1
1.809e+40
0.2
17
A1g
373
373
373
373
1.071e+43
99.3
7.649e+40
0.7
1.079e+43
100.0
18
B3u
410
410
410
410
19
B1u
508
508
508
516
20
B2g
516
516
516
545
1.325e+40
0.1
1.821e+40
0.2
3.146e+40
0.3
21
B1u
596
596
596
596
8.777e+41
8.1
1.207e+42
11.2
2.085e+42
19.3
22
B2g
597
597
597
599
23
B3u
629
638
629
629
24
A1g
638
699
638
638
6.179e+39
0.1
7.932e+38
0.0
6.973e+39
0.1
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.