- DIAMOND (6H) - C

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:	194		P6_3/mmc
Lattice parameters (Å):
Angles (°):	90	90		120

Symmetry (theoretical):

Space group:	194		P6_3/mmc
Lattice parameters (Å):	2.4829	2.4829		12.2469
Angles (°):	90	90		120

Cell contents:

Number of atoms:	12
Number of atom types:	1
Chemical composition:	0

Atomic positions (theoretical):

C:	1.0000	1.0000	0.9983
C:	1.0000	1.0000	0.1246
C:	0.3333	0.6667	0.1664
C:	0.3333	0.6667	0.2907
C:	0.6667	0.3333	0.3322
C:	0.6667	0.3333	0.4565
C:	1.0000	1.0000	0.4983
C:	1.0000	1.0000	0.6246
C:	0.6667	0.3333	0.6664
C:	0.6667	0.3333	0.7907
C:	0.3333	0.6667	0.8322
C:	0.3333	0.6667	0.9565

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	E2u	292	292	292	292	1.927e+36 0.0	1.330e+36 0.0	3.257e+36 0.0
5	E2u	292	292	292	292
6	E2g	303	303	303	303	5.510e+38 0.3	4.375e+38 0.2	9.885e+38 0.5
7	E2g	303	303	303	303	5.435e+38 0.3	7.240e+38 0.4	1.267e+39 0.7
8	E1g	481	481	481	481	1.171e+39 0.6	1.689e+39 0.9	2.860e+39 1.5
9	E1g	481	481	481	481	1.171e+39 0.6	1.532e+39 0.8	2.703e+39 1.4
10	B1g	494	494	494	494
11	E1u	495	495	495	495
12	E1u	495	495	495	495
13	B2u	500	500	500	500
14	E2u	549	549	549	549
15	E2u	549	549	549	549
16	A2u	889	889	889	889	4.044e+36 0.0	6.654e+36 0.0	1.070e+37 0.0
17	A1g	894	894	894	894	1.718e+39 0.9	6.787e+37 0.0	1.786e+39 1.0
18	B2u	1077	1077	1077	1077
19	E2g	1232	1232	1232	1232	1.077e+40 5.7	8.237e+39 4.4	1.901e+40 10.1
20	E2g	1232	1232	1232	1232	1.076e+40 5.7	1.464e+40 7.8	2.540e+40 13.5
21	E1u	1246	1246	1246	1246	1.356e+36 0.0	1.158e+36 0.0	2.514e+36 0.0
22	E1u	1246	1246	1246	1246
23	E1g	1260	1260	1260	1260	8.937e+38 0.5	1.229e+39 0.7	2.123e+39 1.1
24	E1g	1260	1260	1260	1260	8.939e+38 0.5	1.229e+39 0.7	2.123e+39 1.1
25	B1g	1270	1270	1270	1270	1.351e+36 0.0	1.492e+36 0.0	2.844e+36 0.0
26	A1g	1299	1299	1299	1299	8.305e+40 44.3	5.266e+40 28.1	1.357e+41 72.3
27	E2g	1301	1301	1301	1301	8.617e+40 45.9	8.165e+40 43.5	1.678e+41 89.4
28	E2g	1301	1301	1301	1301	8.618e+40 45.9	1.015e+41 54.1	1.876e+41 100.0
29	E2u	1302	1302	1302	1302
30	E2u	1302	1302	1302	1302
31	B2u	1318	1318	1318	1318
32	A2u	1322	1322	1322	1322	2.242e+36 0.0	3.690e+36 0.0	5.932e+36 0.0
33	E1g	1331	1331	1331	1331	6.865e+40 36.6	9.448e+40 50.3	1.631e+41 86.9
34	E1g	1331	1331	1331	1331	6.865e+40 36.6	9.432e+40 50.3	1.630e+41 86.9
35	A1g	1332	1332	1332	1332	9.846e+40 52.5	7.383e+40 39.3	1.723e+41 91.8
36	B1g	1342	1342	1342	1342	1.530e+36 0.0	1.690e+36 0.0	3.220e+36 0.0

No.

Char.

ω TO

ω LOx

ω LOy

ω LOz

I ∥

I ⊥