Vibrational excitation of H2 scattering from Cu(111): Effects of surface temperature and of allowing energy exchange with the surface

Theoretical Chemistr

Electronic Friction-Based Vibrational Lifetimes of Molecular Adsorbates: Beyond the Independent-Atom Approximation

Catalysis and Surface ChemistryTheoretical Chemistr

Femtosecond-laser induced dynamics of CO on Ru(0001): Deep insights from a hot-electron friction model including surface motion

Theoretical Chemistr

Reactive and Nonreactive Scattering of HCl from Au(111): An Ab Initio Molecular Dynamics Study

The HCl + Au(111) system has recently become a benchmark for highly activated dissociative chemisorption, which presumably is strongly affected by electron–hole pair excitation. Previous dynamics calculations, which were based on density functional theory at the generalized gradient approximation level (GGA-DFT) for the molecule–surface interaction, have all overestimated measured reaction probabilities by at least an order of magnitude. Here, we perform ab initio molecular dynamics (AIMD) and AIMD with electronic friction (AIMDEF) calculations employing a density functional that includes the attractive van der Waals interaction. Our calculations model the simultaneous and possibly synergistic effects of surface temperature, surface atom motion, electron–hole pair excitation, the molecular beam conditions of the experiments, and the van der Waals interaction on the reactivity. We find that reaction probabilities computed with AIMDEF and the SRP32-vdW functional still overestimate the measured reaction probabilities, by a factor 18 for the highest incidence energy at which measurements were performed (≈2.5 eV). Even granting that the experiment could have underestimated the sticking probability by about a factor three, this still translates into a considerable overestimation of the reactivity by the current theory. Likewise, scaled transition probabilities for vibrational excitation from ν = 1, j = 1 to ν = 2 are overestimated by the AIMDEF theory, by factors 3–8 depending on the initial conditions modeled. Energy losses to the surface and translational energy losses are, however, in good agreement with experimental values.Theoretical Chemistr

Angular distributions and rovibrational excitation of N2 molecules recombined on N-covered Ag(1 1 1) by the Eley?Rideal mechanism

Former calculations showed that atomic N incident at energies of a few eV on N-covered Ag(1 1 1) forms N2 molecules by the Eley?Rideal (ER) mechanism, i.e. by direct pick-up of adsorbates. Here, we calculate the azimuthal angle distributions and the rovibrational energies of those ER products. We observe a non-trivial angle dependence that may result in very low in-plane ER yield for some given incident azimuthal angles. We find that most of the energy released upon N N bond formation, about 7 eV, is stored in the rovibrational degrees of freedom independently of the incidence energy considered.Fil: Juaristi, J.I.. Departamento de Física de Materiales, Facultad de Químicas UPV/EHU; España. Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU); España. Donostia International Physics Center; EspañaFil: Díaz, E.. Donostia International Physics Center; EspañaFil: Bocan, Gisela Anahí. Comisión Nacional de Energía Atómica; Argentina. Comision Nacional de Investigacion Cientifica y Tecnologica; ChileFil: Alducin, M.. Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU); España. Donostia International Physics Center; EspañaFil: Díez Muino, R.. Centro de Física de Materiales CFM/MPC (CSIC-UPV/EHU); España. Donostia International Physics Center; EspañaFil: Blanco-Rey, M.. Departamento de Física de Materiales, Facultad de Químicas UPV/EHU; España. Donostia International Physics Center; Españ