Accurate absolute core-electron binding energies of molecules, solids, and surfaces from first-principles calculations

Core-electron x-ray photoelectron spectroscopy is a powerful technique for studying the electronic structure and chemical composition of molecules, solids, and surfaces, but the interpretation of measured spectra and the assignment of peaks to atoms in specific chemical environments is often challenging. Here, we address this problem and demonstrate that accurate absolute core-electron binding energies can be obtained from the total energy difference of the ground state and a state with an explicit core hole when exchange and correlation effects are described by the strongly constrained and appropriately normed metageneralized gradient approximation and relativistic effects are included self-consistently even for light elements. We carry out calculations for molecules, solids, and surface species and find excellent agreement with available experimental measurements. For example, we find a mean absolute error of only 0.16 eV for a reference set of 103 molecular core-electron binding energies.