Ab initio simulation of the spin transition during chemisorption: H/Al(111).

Electronically nonadiabatic effects during the chemisorption of hydrogen atoms on an Al(111) surface are simulated ab initio using time-dependent density-functional theory for the electrons in combination with Ehrenfest dynamics for the nuclei. Strongly nonadiabatic effects close to the spin transition of the H atom are identified, and the dissipated energy as well as the electron-hole pair excitation spectra are calculated. The recent Newns-Anderson-model approach by Mizielinski et al. is confirmed. The simulations illustrate the physical processes that contribute to internal exoelectron emission.