Theoretical study of the molecular-frame photoemission time delay for K -shell photoionization of N2

Photoelectron emission Wigner time delay for K-shell ionization of a nitrogen molecule is studied theoretically in the frame of a molecular reference for parallel and perpendicular orientations of the molecule with respect to the electric field vector of linearly polarized ionizing light. Electronic structure calculations are performed by the single center method for photoelectron kinetic energies from 5 to 20 eV and at different levels of approximation. Thereby, the influence of core relaxation effects and interchannel coupling on the 1s-photoemission time delays, computed across the σ∗-shape resonance, is investigated in detail. The present theoretical results can be considered as reliable predictions for future experiments.