PSIXAS: A Psi4 plugin for efficient simulations of X‐ray absorption spectra based on the transition‐potential and Δ‐Kohn–Sham method

Near edge X‐ray absorption fine structure (NEXAFS) spectra and their pump‐probe extension (PP‐NEXAFS) offer insights into valence‐ and core‐excited states. We present PSIXAS, a recent implementation for simulating NEXAFS and PP‐NEXAFS spectra by means of the transition‐potential and the Δ‐Kohn–Sham method. The approach is implemented in form of a software plugin for the Psi4 code, which provides access to a wide selection of basis sets as well...