Atomistic methods applied to the study of structural and electronic properties of nanomaterials

Abstract

This proposal, besides its scientific content, aims to update the installation of a computational structure which has been used by my research group in the last 6 years as a professor atthe Physics Department of São Paulo State University. This computational structure has beenused to develop computational models and codes applied to atomistic simulations of nanoscopic systems. This computational simulation laboratory had its initial structures installedwith the financial support held by Fapesp (Grant 2011/17253-3) and other funding agencies,like CNPq and Fundunesp. Furthermore, the present project proposes the deepening of studies carried in the last few years regarding the nanoscaled systems, specially two-dimensionalones. Another important point to highlight here is the fact that the proposed studies are completely harmonious with the long term collaboration already established with Professor Adrivan Duin's group, at Penn State University (US). In the present moment, we are stablishinga new line of scientific work in which new parametrizations for the approximation knownas Tight Binding Density Functional Theory(DFTB) will be developed. DFTB, as a DFTapproximation, allows quantum calculations for atomistic structures containing large numberof atoms (hundreds or thousands, depending on the available computational resources). Thisnew line of work is being stablished with the collaboration of Prof. Pekka Koskinen, fromJyväskylä University (Finland). These two methodologies can be applied in a complementaryway in order to understand and construct computational models to describe the behavior ofatomistic systems with large number of atoms. Mechanical and structural properties can beinvestigated using ReaxFF, while electronic structure or transport effects can be investigated describing atomic interactions through DFTB approximation. During the period of theproject, we are going to investigate structural, mechanical and electronic properties of lowdimensional systems, with special interest in two-dimensional structures. Among the systemsof interest we have porous graphene, octagraphene and similar structures composed of carbon atoms and/or combinations of boron and nitrogen, and also two-dimensional materials whichare candidates for auxetic behavior. Taking into account mechanical, electronic and transportproperies of the new proposed materials, we are going to investigate the the effects obtainedby the adsorption of transition metal atoms on these structures. To this part of the project,new DFTB parametrizations will be very important in order to describe the relevant atomicinteractions. (AU)