Al(111)-(root 3X root 3)R30: On-top versus substitutional adsorption for Rb and K

Article

关键词: DENSITY-FUNCTIONAL THEORY;    ALKALI-METAL ADSORPTION;    POLY-ATOMIC SYSTEMS;    ELECTRONIC-STRUCTURE;    AL(111);    TRANSITION;    SURFACES;    SITES;    PSEUDOPOTENTIALS;    IDENTIFICATION;   

DOI  :  10.1103/PhysRevB.68.035403

来源: SCIE

【 摘 要 】

The atomic structure and energetics of the on-top and substitutional phase of the Al(111)-(root3 X root3)R30:Rb adsorbate system have been studied employing density-functional-theory total-energy calculations. Since the energy difference between the two phases is extremely small (approximate to20 meV) extensive checks with respect to the choice of the exchange-correlation functional (local density and generalized gradient approximations) and the construction of the Rb pseudopotential have been performed. All tests clearly show the substitutional adsorption site to be energetically favorable. Equivalent calculations performed for K revealed a clear chemical trend in the adsorption energetics for Na, K, and Rb: The energy gain between the substitutional and the on-top configuration decreases with increasing atomic radius of an alkali atom. The calculated equilibrium geometries are in good agreement with previously reported experimental data.

【 授权许可】

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