Real-time study of the adiabatic energy loss in an atomic collision with a metal cluster

The phenomena of the adiabatic energy loss in an atomic collision with a metal cluster was studied. The electrons were treated realistically using standard approximations to time-dependent density functional theory. It was observed that the electronic excitations produce a frictionlike force on the gas-phase hydrogen atoms. The results show that the friction coefficient strongly depends on the direction of the motion of the atom.