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Abstract

In honoring the seminal contribution of Henry Eyring and Michael Polanyi who first introduced theconcept of potential energy surfaces (PESs) to describe chemical reactions in gas-phase [Z. Phys.Chem. 12, 279–311, (1931)], this work comes to review and assess state-of-the-art approachestowards first-principle based modeling in the field of gas-surface dynamics. Within the Born-Oppenheimer and frozen surface approximations, the O₂-Ag(100) interaction energetics are usedas a showcase system to accentuate the complex landscape exhibited by the PESs employed todescribe the impingement of diatomics on metal substrates and draw attention to the far-from-trivialtask of continuously representing them within all six molecular degrees of freedom. To this end,the same set ofab initioreference data obtained within Density Functional Theory (DFT) arecontinuously represented by two different state-of-the-art high-dimensional approaches, namely theCorrugation-Reducing Procedure and Neural Networks. Exploiting the numerically undemandingnature of the resulting representations, a detailed static evaluation is performed on both PESs basedon an extensive global minima search. The latter proved particularly illuminating in revealingrepresentation deficiencies which affect the dynamical picture yet go otherwise unnoticed withinthe so-called “divide-and-conquer” approach.