Ab Initio Modeling of MultiWall: A General Algorithm First Applied to Carbon Nanotubes.

Naiara Leticia Marana,Silvia Casassa,Chiara Ribaldone,Yves Noel,Julio Ricardo Sambrano

doi:10.1021/acs.jpca.1c01682

Abstract

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.

Highlights

In the last decades, with the advancement of nanotechnology, different structures emerged, characterized by promising and appealing properties
In 2010, Noel and co-workers2 implemented in the CRYSTAL program an original algorithm that fully exploits the helical symmetry in a periodic contest and allows the modeling and simulation of single-wall nanotubes (SWNTs)
In documenting and exploring the limitations and potential of the new tool, we have provided a first glimpse of challenging problems such as the spectroscopic characterization of multiwall carbon nanotubes (MWCNT) and the engineering of semiconductor MWCNT to be exploited in thermoelectric devices

Summary

Introduction

With the advancement of nanotechnology, different structures emerged, characterized by promising and appealing properties. Alongside the synthesis and the experimental characterization of such materials, the development of reliable computational tools can be a good way to assess their fundamental properties and explore the effects of chiralities, thickness, and doping process to obtain a preliminary screening of potentially interesting systems for technological and scientific applications. With this goal, in 2010, Noel and co-workers implemented in the CRYSTAL program an original algorithm that fully exploits the helical symmetry in a periodic contest and allows the modeling and simulation of single-wall nanotubes (SWNTs).. As far as we know, few studies have been done on multiwall (MW) systems, perhaps for this very reason

Methods

Results

Conclusion