  A high-dimensional potential energy surface (PES) for CO interaction with the
Au(111) surface is developed using a machine-learning algorithm. Including both
molecular and surface coordinates, this PES enables the simulation of the
recent experiment on scattering of vibrationally excited CO from Au(111).
Trapping in a physisorption well is observed to increase with decreasing
incidence energy. While energy dissipation of physisorbed CO is slow, due to
weak coupling with both the phonons and electron-hole pairs, its access to the
chemisorption well facilitates fast vibrational relaxation of CO through
nonadiabatic coupling with surface electron-hole pairs.
