Regensburg 2004 – wissenschaftliches Programm

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O: Oberflächenphysik

O 14: Postersitzung (Adsorption an Oberflächen, Epitaxie und Wachstum, Organische Dünnschichten, Oxide und Isolatoren, Phasenübergänge, Rastersondentechniken, Struktur und Dynamik reiner Oberflächen)

O 14.16: Poster

Montag, 8. März 2004, 18:00–21:00, Bereich C

Excited potential energy surface from spin-restricted density-functional calculations: H/Al(111) — •Michael Lindenblatt and Eckhard Pehlke — Institut für Theoretische Physik und Astrophysik, Universität Kiel

Excited-state potential-energy surfaces are needed for the description of non-adiabatic processes during chemisorption, such as the loss of spin-polarization of an atom which is approaching a metal surface. A process of this type has been discussed as a possible explanation for the chemicurrents observed experimentally by H. Nienhaus et al.[1],[2].

To compute potential-energy surfaces of spin-polarized configurations away from the Born-Oppenheimer ground state we have carried out spin-restricted (fixed moment) density-functional calculations with the code fhi96spin (from M. Bockstedte et al.[3]). To prevent the spin-polarization from spreading over the whole metal slab at small atom-surface separation, we apply an additional potential. As an example, we present potential-energy surfaces for H/Al(111).

[1] H. Nienhaus, Surf. Sci. Rep. 45, 1 (2002).

[2] J. R. Trail et al. , J. Chem. Phys. 119, 4539 (2003).

[3] M. Bockstedte, A. Kley, J. Neugebauer, M. Scheffler, Comp. Phys. Commun. 107, 187 (1997).