Geometry, and Normal Modes of Vibration (3N-6) for Di and Tetra-Rings Layer (6, 0) Linear (Zigzag) SWCNTs; A DFT Treatment. Baghdad Sci.J 2019, 16 (3(Suppl.), 0726. https://doi.org/10.21123/bsj.2019.16.3(Suppl.).0726.