Table 2. Symmetry representation for phonon modes in bulk and few layer TMDCs14.
| # of Layers | Sym. Grp. | σh/i Sym. | S | B | IC | OC | IMC | OMC |
|---|---|---|---|---|---|---|---|---|
| 1 | D3h | + | − | − | − | 1 A’1 | 1 E’ | − |
| − | − | − | 1 E” | − | − | 1 A”2 | ||
| 2 | D3d | + | 1 Eg | 1 A1g | 1 Eg | 1 A1g | 1 Eg | 1 A1g |
| − | − | − | 1 Eu | 1 A2u | 1 Eu | 1 A2u | ||
| 3 | D3h | + | 1 E’ | 1 A’1 | 1 E’ | 2 A’1 | 2 E’ | 1 A’1 |
| − | 1 E” | 1 A”2 | 2 E” | 1 A”2 | 1 E” | 2 A”2 | ||
| 4 | D3d | + | 2 Eg | 2 A1g | 2 Eg | 2 A1g | 2 Eg | 2 A1g |
| − | 1 Eu | 1 A2u | 2Eu | 2 A2u | 1 Eu | 2 A2u | ||
| 5 | D3h | + | 2 E’ | 2 A’1 | 2 E’ | 3 A’1 | 3 E’ | 2 A’1 |
| − | 2 E” | 2 A”2 | 3 E” | 2 A”2 | 2 E” | 3 A”2 | ||
| bulk | D46h | + | 1 E2g | 1 B2g | 1 E1g | 1 A1g | 1 E2g | 1 B2g |
| − | − | − | 1 E2u | 1 B1u | 1 E1u | 1 A2u |
The third column specifies whether the mode is even or odd under horizontal mirror plane reflection/inversion. Raman active modes (in back scattering geometry) are colored in bold red.