Spin density distributions on graphene clusters and ribbons with carbene-like active sites.

Aiming to better understand the reactivity of graphene-based materials, the present work employs density functional theory that provides detailed information about spin-density distributions for single and contiguous pairs of carbene-like active sites. In order to examine the extent to which different models, methodologies, and approximations affect the outcome, our calculations employ the AIMPRO, QuantumEspresso and Gaussian program packages. Models are in the form of polycyclic aromatic hydrocarbons (PAHs) and graphene nanoribbons (GNRs), both isolated and within supercells with periodic boundary conditions.