-    MONTROYDITE     -    HgO

Experimental structure. Atomic position and lattice parameters from 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:  8 
Number of atom types:  2 
Chemical composition:  0 

Atomic positions (theoretical):

Hg:  0.1136  0.2500  0.2456 
O:  0.3592  0.2500  0.5955 
Hg:  0.3864  0.7500  0.7456 
O:  0.1408  0.7500  0.0955 
Hg:  0.8864  0.7500  0.7544 
O:  0.6408  0.7500  0.4045 
Hg:  0.6136  0.2500  0.2544 
O:  0.8592  0.2500  0.9045 
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
A1g
33
33
33
33
2.096e+40
0.1
5.688e+39
0.0
2.665e+40
0.2
5
B2g
40
40
40
40
8.419e+38
0.0
1.158e+39
0.0
2.000e+39
0.0
6
B3u
54
57
54
54
7
A1g
57
58
57
57
4.108e+39
0.0
5.304e+38
0.0
4.639e+39
0.0
8
Au
58
59
58
58
9
B3g
59
59
59
59
1.114e+41
0.8
1.532e+41
1.1
2.646e+41
1.8
10
B1g
76
76
76
76
1.668e+39
0.0
2.294e+39
0.0
3.962e+39
0.0
11
Au
88
88
88
88
1.496e+41
1.0
2.057e+41
1.4
3.553e+41
2.5
12
B3g
90
90
90
90
13
B2g
134
134
138
134
14
B2u
138
138
143
138
1.976e+39
0.0
2.717e+39
0.0
4.693e+39
0.0
15
B1u
143
143
237
150
16
B1g
237
237
257
237
2.281e+40
0.2
3.136e+40
0.2
5.417e+40
0.4
17
A1g
358
358
358
358
1.423e+43
99.0
1.378e+41
1.0
1.437e+43
100.0
18
B3u
395
396
395
395
19
B1u
493
493
493
493
1.302e+41
0.9
1.791e+41
1.2
3.093e+41
2.2
20
B2g
498
498
498
534
21
B1u
557
557
557
563
22
B2g
578
578
578
578
1.035e+42
7.2
1.424e+42
9.9
2.459e+42
17.1
23
B3u
599
606
599
599
24
A1g
606
668
606
606
6.036e+40
0.4
1.132e+39
0.0
6.149e+40
0.4
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.