Title: Mode specific electronic friction in dissociative chemisorption on metal surfaces: H$_2$ on Ag(111),
Abstract: Electronic friction and the ensuing nonadiabatic energy loss play an
important role in chemical reaction dynamics at metal surfaces. Using molecular
dynamics with electronic friction evaluated on-the-fly from Density Functional
Theory, we find strong mode dependence and a dominance of nonadiabatic energy
loss along the bond stretch coordinate for scattering and dissociative
chemisorption of H$_2$ on the Ag(111) surface. Exemplary trajectories with
varying initial conditions indicate that this mode-specificity translates into
modulated energy loss during a dissociative chemisorption event. Despite minor
nonadiabatic energy loss of about 5\%, the directionality of friction forces
induces dynamical steering that affects individual reaction outcomes,
specifically for low-incidence energies and vibrationally excited molecules.
Mode-specific friction induces enhanced loss of rovibrational rather than
translational energy and will be most visible in its effect on final energy
distributions in molecular scattering experiments.