title: Quantum dynamics of hydrogen atoms on graphene. II. Sticking.
abstract: Following our recent system-bath modeling of the interaction between a hydrogen atom and a graphene surface [Bonfanti et al., J. Chem. Phys. 143, 124703 (2015)], we present the results of converged quantum scattering calculations on the activated sticking dynamics. The focus of this study is the collinear scattering on a surface at zero temperature, which is treated with high-dimensional wavepacket propagations with the multi-configuration time-dependent Hartree method. At low collision energies, barrier-crossing dominates the sticking and any projectile that overcomes the barrier gets trapped in the chemisorption well. However, at high collision energies, energy transfer to the surface is a limiting factor, and fast H atoms hardly dissipate their excess energy and stick on the surface. As a consequence, the sticking coefficient is maximum (∼0.65) at an energy which is about one and half larger than the barrier height. Comparison of the results with classical and quasi-classical calculations shows that quantum fluctuations of the lattice play a primary role in the dynamics. A simple impulsive model describing the collision of a classical projectile with a quantum surface is developed which reproduces the quantum results remarkably well for all but the lowest energies, thereby capturing the essential physics of the activated sticking dynamics investigated.
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Milano, v. Golgi 19, 20133 Milano, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Bonfanti
authors.affiliation: Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, USA.
authors.forename: Bret
authors.initials: B
authors.lastname: Jackson
authors.affiliation: School of Chemistry, Bangor University, Bangor, Gwynedd LL57 2UW, United Kingdom.
authors.forename: Keith H
authors.initials: KH
authors.lastname: Hughes
authors.affiliation: Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 7, 60438 Frankfurt/Main, Germany.
authors.forename: Irene
authors.initials: I
authors.lastname: Burghardt
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Milano, v. Golgi 19, 20133 Milano, Italy.
authors.forename: Rocco
authors.initials: R
authors.lastname: Martinazzo