Exceptional Spatial Variation of Charge Injection Energies on Plasmonic Surfaces

Impact of Subsurface Oxygen on CO2 Charging Energy Changes in Cu Surfaces

Subsurface oxygen in oxide-derived copper catalysts significantly influences CO2 activation. However, its effect on the molecular charging process, the key to forming the CO2δ- intermediate, remains poorly understood. We employ many-body perturbation theory to investigate the impact of the structural factors induced by the subsurface oxygen on the charged activation of CO2. By computing the molecular single-particle state energy of the electron-accepting orbital on the Cu (111) surface, we examined how this molecular quasi-particle (QP) energy changes with the varying vicinity of adsorption and multiple-subsurface oxygen configuration. We demonstrate that subsurface oxygen impairs CO2 charging, with its presence and coverage being influential factors. However, we remark that density functional theory calculations do not predict such an excitation energy discrepancy induced by subsurface oxygen. The nonlocal potential proves to be substantial for accurate excitation energy predictions yet is not sensitive to minor atomic structural changes. More importantly, state delocalization and hybridization are critical for determining QP energy. These insights are enlightening for designing atomic architectures to optimize catalytic performance on modified surfaces.

Efficient Quasiparticle Determination beyond the Diagonal Approximation via Random Compression

Calculations of excited states in the Green's function formalism often invokes the diagonal approximation, in which the quasiparticle states are taken from a mean-field calculation. In this paper, we extend the stochastic approaches applied in the many-body perturbation theory and overcome this limitation for large systems in which we are interested in a small subset of states. We separate the problem into a core subspace whose coupling to the remainder of the system environment is stochastically sampled. This method is exemplified on computing hole injection energies into CO2 on an extended gold surface with nearly 3000 electrons. We find that in the extended system the size of the problem can be compressed up to 95% using stochastic sampling. This result provides a way forward for self-consistent stochastic methods and determination of Dyson orbitals in large systems.