Marana Naiara Leticia, Noel Yves, Sambrano Julio Ricardo, Ribaldone Chiara, Casassa Silvia
Modeling and Molecular Simulation Group-CDMF, São Paulo State University, UNESP, 17033-360 Bauru, SP, Brazil.
Theoretical Group of Chemistry, Chemistry Department I.F.M., Torino University, Torino 10124, Italy.
J Phys Chem A. 2021 May 13;125(18):4003-4012. doi: 10.1021/acs.jpca.1c01682. Epub 2021 Apr 28.
A general, versatile and automated computational algorithm to design any type of multiwall nanotubes of any chiralities is presented for the first time. It can be applied to rolling up surfaces obtained from cubic, hexagonal, and orthorhombic lattices. Full exploitation of the helical symmetry permits a drastic reduction of the computational cost and therefore opens to the study of realistic systems. As a test case, the structural, electronic, mechanical, and transport properties of multiwall carbon nanotubes (MWCNT) are calculated using a density functional theory approach, and results are compared with those of the corresponding layered (graphene-like) precursors. The interaction between layers has a general minimum for the inter-wall distance of ≈3.4 Å, in good agreement with experimental and computed optimal distances in graphene sheets. The metallic armchair and semiconductor zigzag MWCNT are almost isoenergetic and their stability increases as the number of walls increases. The vibrational fingerprint provides a reliable tool to identify the chirality and the thickness of the nanostructures. Finally, some promising thermoelectric features of the semiconductor MWCNT are reproduced and discussed.
首次提出了一种通用、多功能且自动化的计算算法，用于设计任意手性的任何类型的多壁纳米管。它可应用于由立方晶格、六方晶格和正交晶格得到的卷曲表面。对螺旋对称性的充分利用极大地降低了计算成本，从而开启了对实际体系的研究。作为一个测试案例，使用密度泛函理论方法计算了多壁碳纳米管（MWCNT）的结构、电子、力学和输运性质，并将结果与相应的层状（类石墨烯）前驱体的结果进行了比较。层间相互作用在壁间距约为3.4 Å时通常具有最小值，这与石墨烯片中的实验和计算得到的最佳距离非常吻合。金属扶手椅型和半导体锯齿型MWCNT几乎具有相同的能量，并且它们的稳定性随着壁数的增加而增加。振动指纹图谱为识别纳米结构的手性和厚度提供了可靠的工具。最后，对半导体MWCNT一些有前景的热电特性进行了再现和讨论。
