Algorithm for constructing full-atomic models of X- and T-shaped seamless junctions between single-walled carbon nanotubes

Modeling the formation of junctions between single-walled carbon nanotubes (SWCNTs) requires large computational resources, which makes it difficult to obtain a large statistical sample of such models, which is necessary to solve a number of problems, in particular, studying the electronic conductivity of materials based on SWCNTs. The need for a statistical sample is due to the fact that there can be many variants of possible junctions between SWCNTs, and the properties of such junctions can be different, taking into account the possible contribution of each defect to the junction conductivity. To simplify obtaining of statistical sampling of junction models, a special algorithm is developed. It allows us to significantly reduce time to build full-atomic models of X- and T-shaped seamless junctions between SWCNTs of different chiralities. Within the framework of the created algorithm, carbon surface formation is modeled by adding carbon atoms in the region with unsaturated bonds in stages, followed by optimization of the mutual arrangement of atoms by molecular dynamics using empirical potentials to describe the interaction between atoms. The created algorithm is implemented in SeamMaker software package developed in Python and C++. To create a statistical sample, it is necessary to indicate the chirality of the connected SWCNTs (moreover, the junction of tubes of different chiralities is permissible) and the type of junction of interest (X- or T-shaped). Full-atomic models constructed using the proposed algorithm can be used to study the influence of the topology of complex branched carbon structures on their mechanical and electroconductive properties.

1. Russian Foundation for Basic Research - 18-32-00610
2. Council on grants of the President of the Russian Federation - SP-892.2018.1