In the present work two main simulations scheme are adopted: a semi- empirical quantum mechanical approach based on the tight-binding scheme,
that shows some notable properties like a better computational efficiency (allowing simulation cells with ∼ 103 atoms) or a simple treatment of dy- namical process at the nano-scale and first principles calculations based on the density functional theory (DFT), much more computationally demanding and that have been mainly used for the validation of the tight binding parameters and results. Static electronic structure calculations and molecular dynamics have been performed to study the optoelectronic properties of nanocrystalline silicon (nc-Si) and the chemical reaction of methane adsorption at the sidewall of a CNT respectively
