Selection of the optimal parameters for simulation of atomic and electronic structure of carbon nanotubes by SIESTA package

In connection with the development and the increasing availability of computer modeling of materials based on the first principles, and the emergence of conflicting data about the results of their use there are attempts to justify the use of computing technology on the example of the promising applications of systems - carbon nanotubes. Issues related to the selection of geometric parameters of the model (diameter, length, tube symmetry), ways to optimize its starting configuration, the selection of approximations required to describe electronic structure in the framework of functional electron density theory are discussed. Arguments are supported by the reference to the experience gained by the authors earlier, as well as a variety of calculations carried out specifically in the preparation of this paper.