Absence of isotope effects in the photo-induced desorption of CO from saturated Pd(111) at high laser fluence

• Published in: Chemical physics 2022-06, Vol.558, p.111518, Article 111518
• Main Authors: Muzas, A.S., Serrano Jiménez, Alfredo, Ovčar, Juraj, Lončarić, Ivor, Alducin, Maite, Juaristi, J. Iñaki
• Format: Article
• Language: English
• Subjects: Carbon monoxide; Isotope effect; Langevin dynamics; Neural network; Palladium surface; Photo-induced desorption
• ISSN: 0301-0104
• DOI: 10.1016/j.chemphys.2022.111518

•Accurate neural network PES allows simulating long lasting photo desorption dynamics.•We propose an environment distance function to validate the long lasting dynamics.•We search for isotope effects in the photo desorption of CO from Pd(111) with 0.75ML.•No isotope effects found in the CO desorption probability at large laser fluence.•Sizable isotope effects appear in the vibrational excitation of the fastest CO. Neural network-based potential energy surfaces are currently gaining relevance in the context of gas-solid dynamics. In this work, we use this methodology to theoretically explore femtosecond laser pulse induced desorption of CO from the Pd(111) surface with a coverage of 0.75 ML. We performed molecular dynamics simulations in the high laser fluence regime on two different CO isotopes, 12C16O and 13C18O, in order to search for possible isotope effects affecting the photo-induced desorption. According to our findings, isotope effects of relevance do not appear in desorption probabilities once the whole process has finished after 50 ps. However, for those molecules desorbed with the highest translational kinetic energies, we obtain that 12C16O molecules are more vibrationally excited than 13C18O. This mostly happens as a consequence of the interaction of adsorbed CO with the laser-excited electrons in the substrate.