Graphene to graphite: electronic changes within DFT calculations

Graphene to graphite: electronic changes within DFT calculations

Calculations based on the first-principles pseudopotential plane-wave method and density-functional theory are performed to investigate the electronic properties of graphene, bilayer graphene, multilayer graphene, and graphite. From an analysis of the electronic band structure close to the Fermi level, we have quantified the gradual change in the Fermi surface topology from the point-like struc...

Electronic Behavior of Doped Graphene Nanoribbon Device: NEGF+DFT

Quantum transport properties of pure and functioned infinite lead-connection region-lead systembased on the zigzag graphene nanoribbon (2-zGNR) have been investigated. In this work the effectof the doping functionalization on the quantum transport of the 2-zGNR has been computationallystudied. Also, the effect of the imposed gate voltages (-3.0, 0.0 and +3.0 V) and bias voltages 0.0 to2.0 V hav...

Adsorption of beryllium on graphene and graphite by DFT 1 Adsorption of Beryllium Atoms and Clusters on Graphene and in a Bilayer of Graphite Investigated by DFT

We herein investigate the interaction of beryllium with a graphene sheet and in a bilayer of graphite by means of periodic DFT calculations. In all cases, we find the beryllium atoms to be more weakly bonded on graphene than in the bilayer. Be2 forms both magnetic and non-magnetic structures on graphene depending on the geometrical configuration of adsorption. We find the stability of the Be/bi...

Electronic Structure Calculations at Macroscopic Scales using Orbital-free DFT

In this chapter we provide an overview of the recently developed coarse-graining technique for orbital-free density functional theory that enables electronic structure calculations on multi-million atoms. The key ideas involved are: (i) a local real-space formulation of orbital-free density functional theory; (ii) a finite element discretization of the formulation; (iii) a systematic means of a...

Parallelization of DFT calculations within the real space grid approach