| RBM frequency (cm−1) | Diameter (nm) | Assignment (n, m) |
| 271 | 0.92 | metal (9, 3) |
| 263 | 0.94 | metal (8, 5) |
| 248 | 1.0 | metal (12, 0) |
| 209 | 1.2 | semiconductor (12, 4) |
| 188 | 1.3 | semiconductor (16, 0) |