Atomic and molecular scattering at semiconductor interfaces plays a central role in surface chemistry and catalysis, yet predictive simulations remain challenging due to strong nonadiabatic effects, causing the breakdown of the Born–Oppenheimer approximation. Here, we present fully quantum simulations of H-atom scattering from the Ge(111)c(2 × 8) rest site using the hierarchical equations of motion (HEOM) with matrix product states. The system is modeled by mapping a density functional theory potential energy surface onto a Newns–Anderson Hamiltonian. Our simulations reproduce the experimentally observed bimodal kinetic energy distributions, capturing both elastic and energy-loss channels. By systematically examining atom–surface coupling, incident energy, and isotope substitution, we identify the strong-coupling regime required to recover the experimental energy-loss profile. This regime suppresses the elastic peak, implying additional site-specific scattering channels in the observed elastic peak. Deuterium substitution further produces a subtle shift in the energy-loss peak, consistent with experiment. These results establish HEOM as a rigorous framework for quantum surface scattering, capable of capturing nonadiabatic dynamics beyond electronic friction and perturbative approaches.
Dan et al. (Wed,) studied this question.