title: Surface structure and energetics of hydrogen adsorption on the Fe(111) surface.
abstract: Spin-polarized density functional theory calculations have been performed to characterize the hydrogen adsorption and diffusion on the Fe(111) surface at 2/3-, 1-, and 2-monolayer (ML) coverages. It is found that the most favored adsorption site for atomic hydrogen (H) is the top-shallow bridge site (tsb), followed by the quasi 4-fold site (qff) with the energy difference of about 0.1 eV, while the top site (t) is not competitive. Furthermore, the adsorbed atomic hydrogen (H) has a high mobility, as indicated by the small diffusion barriers. The local density of state (LDOS) analysis reveals that the Fe-H (tsb or qff) bond involves mainly the Fe 4s and 4p and H 1s orbitals with less contribution of the Fe 3d orbital, while the Fe 4s, 4p, and 3d orbitals all participate in the Fe-H (top) bond. In addition, the coverage effects on the adsorption configurations and adsorption energies are addressed.
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, P.R. China.
authors.forename: Chun-Fang
authors.initials: CF
authors.lastname: Huo
authors.forename: Yong-Wang
authors.initials: YW
authors.lastname: Li
authors.forename: Jianguo
authors.initials: J
authors.lastname: Wang
authors.forename: Haijun
authors.initials: H
authors.lastname: Jiao