2026/07/22 by Stefano Paggi, J. Arjan Berger, Pina Romaniello · 1 voice · 1 citation
#cond-mat.other
We recently presented multichannel Dyson equations for the ab initio simulation of various spectroscopies. In particular, we introduced a multichannel Dyson equation for the description of photoemission spectra. In this work, we apply our approach to the simulation of photoemission spectra of atoms and molecules. We introduce a numerically efficient approach to calculate their spectral functions. We compare the spectra obtained within the multichannel Dyson equation to those obtained with full configuration interaction and the GW method. We are thus able to show that the satellite features due to shake-up processes are significantly better described by the multichannel Dyson equation than by GW. Finally, we also discuss the slow convergence of the satellite energies with the size of the basis set and we propose a simple extrapolation method to reach the complete basis-set limit.