Adiabatic and Nonadiabatic Energy Dissipation during Scattering of Vibrationally Excited CO from Au(111)

TL;DR

This study develops a machine-learning-based potential energy surface to simulate vibrationally excited CO scattering from Au(111), revealing insights into energy dissipation mechanisms and vibrational relaxation processes.

Contribution

It introduces a high-dimensional PES for CO-Au(111) interactions that incorporates both molecular and surface coordinates, enabling detailed dynamical simulations.

Findings

Trapping in a physisorption well increases at lower incident energies.

Energy dissipation in physisorbed CO is slow due to weak coupling.

Access to chemisorption facilitates rapid vibrational relaxation via nonadiabatic coupling.

Abstract

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.