- HERZENBERGITE - SnS

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:	62		Pbnm
Lattice parameters (Å):	4.7104	10.2718		8.7476
Angles (°):	90	90		90

Symmetry (theoretical):

Space group:	62		Pbnm
Lattice parameters (Å):	4.0445	10.3365		3.7834
Angles (°):	90	90		90

Cell contents:

Number of atoms:	8
Number of atom types:	2
Chemical composition:	0

Atomic positions (theoretical):

Sn:	0.1176	0.1119	0.2500
S:	0.4555	0.8577	0.2500
Sn:	0.6176	0.3881	0.7500
S:	0.9555	0.6423	0.7500
Sn:	0.8824	0.8881	0.7500
S:	0.5445	0.1423	0.7500
Sn:	0.3824	0.6119	0.2500
S:	0.0445	0.3577	0.2500

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:

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	46	46	46	46	6.914e+42 7.0	2.115e+42 2.1	9.029e+42 9.1
5	Au	59	59	59	59
6	B2g	64	64	64	64	5.495e+41 0.6	7.555e+41 0.8	1.305e+42 1.3
7	B2u	68	68	69	68
8	B3g	87	87	87	87	2.873e+42 2.9	3.950e+42 4.0	6.823e+42 6.9
9	B1g	91	91	91	91	1.337e+41 0.1	1.838e+41 0.2	3.175e+41 0.3
10	B1g	112	112	112	112	1.425e+39 0.0	1.960e+39 0.0	3.386e+39 0.0
11	A1g	114	114	114	114	5.633e+42 5.7	4.201e+42 4.2	9.835e+42 9.9
12	B3u	126	128	126	126
13	B1u	169	169	169	191
14	B2u	191	191	201	201
15	B2g	201	201	207	207	4.174e+43 42.1	5.739e+43 57.9	9.913e+43 100.0
16	B3u	207	227	227	227
17	A1g	227	227	227	227	8.641e+43 87.2	5.790e+42 5.8	9.220e+43 93.0
18	Au	227	237	237	237
19	B3g	237	243	242	243	2.108e+40 0.0	2.898e+40 0.0	5.006e+40 0.1
20	B2u	243	259	266	266
21	B3u	266	273	273	273
22	A1g	273	276	276	276	1.420e+43 14.3	9.928e+41 1.0	1.519e+43 15.3
23	B1g	276	297	297	285	1.288e+42 1.3	1.771e+42 1.8	3.059e+42 3.1
24	B1g	297	310	375	297	8.446e+41 0.9	1.161e+42 1.2	2.006e+42 2.0

No.

Char.

ω TO

ω LOx

ω LOy

ω LOz

I ∥

I ⊥