We have performed optimization of (5,0) zigzag and (5,5) armchair single-walled carbon nanotube and SiC nanotube using density functional theory at zero spin and high spin values. Further, Infrared and Raman spectra, highest occupied and lowest unoccupied molecular orbitals and their gap and natural bond orbital analysis were carried out at optimized structures of these materials. Three different exchange and correlation functionals PBE, LSDA and HCTH along with cc-pVDZ basis set were used. For conspicuous normal modes assignments of both the (5,0) zigzag and (5,5) armchair single-walled carbon nanotube and SiC nanotube, potential energy distributions of the normal modes were calculated using normal coordinate analysis. The diameter of carbon nanotube and SiC nanotube in (5,0) zigzag form were optimized at 4.0 Å and 5.0 Å respectively and in (5,5) armchair form were optimized at 7.0 Å and 8.0 Å respectively at all the three level of theories.

我们使用零旋转和高旋转值下的密度泛函理论对（5,0）之字形和（5,5）扶手椅单壁碳纳米管和SiC纳米管进行了优化。此外，在这些材料的最佳结构上进行了红外和拉曼光谱，最高占据和最低未占据分子轨道及其间隙和自然键轨道分析。使用了三种不同的交换和相关功能PBE，LSDA和HCTH以及cc-pVDZ基集。对于（5,0）之字形和（5,5）扶手椅单壁碳纳米管和SiC纳米管的显着正态分配，使用正态坐标分析计算了正态的势能分布。（5,0）之字形碳纳米管和SiC纳米管的直径分别优化为4.0Å和5.0Å，以及（5，