Laboratory of Theoretical Chemistry, Eotvos University, Budapest H-1518, Hungary.
J Chem Phys. 2010 Jan 21;132(3):034309. doi: 10.1063/1.3292604.
Due to their rotational (C(n)) symmetry, neutral zigzag and armchair type nanotubes possess doubly degenerate orbitals. As the energies of highest occupied molecular orbital and lowest unoccupied molecular orbital are usually different, neutral nanotubes exhibit a nondegenerate ground state. Ionized or excited forms of these tubes, however, may undergo Jahn-Teller distortion if degenerate orbitals show up in the vicinity of the Fermi level. Theoretical calculations in a simple one-eletron-per-site model show that the Jahn-Teller distortion energies are in order-of-magnitude of 0.1 eV for short pieces of tubes, and are associated with a significant geometry change. Distortions tend to diminish quickly with increasing tube length, except if multiple ionizations are considered.
由于其旋转（C(n)）对称性，中性锯齿型和扶手椅型纳米管具有双重简并轨道。由于最高占据分子轨道和最低未占据分子轨道的能量通常不同，因此中性纳米管表现出非简并基态。然而，如果简并轨道出现在费米能级附近，这些管的离子化或激发形式可能会经历 Jahn-Teller 畸变。在一个简单的单电子/位模型中的理论计算表明，对于短管，Jahn-Teller 畸变能在 0.1 eV 的数量级，并且与显著的几何变化相关。除了考虑多次电离之外，除非考虑多次电离，否则随着管长的增加，畸变往往会迅速减小。
