The binding of atomic hydrogen on graphene from density functional theory and diffusion Monte Carlo calculations

In this work, density functional theory (DFT) and diffusion Monte Carlo (DMC) methods are used to calculate the binding energy of a H atom chemisorbed on the graphene surface. The DMC value of the binding energy is about 16% smaller in magnitude than the Perdew-Burke-Ernzerhof (PBE) result. The inclusion of exact exchange through the use of the Heyd-Scuseria-Ernzerhof functional brings the DFT value of the binding energy closer in line with the DMC result. It is also found that there are significant differences in the charge distributions determined using PBE and DMC approaches. Published under an exclusive license by AIP Publishing.

Automated summary

This study uses DFT and DMC methods to calculate the binding energy of a H atom on the graphene surface, and compares the results and influencing factors of the two methods. It is found that the accuracy of the DFT results can be improved by using the HSE functional, and significant differences in charge distributions between the PBE and DMC methods are revealed.