∆SCF Dyson Orbitals and Pole Strengths from Natural Ionization Orbitals

The calculation of photoionization cross-sections can play a key role in spectral assignments using modeling and simulation. In this work, we provide formal relationships between pole strengths, which are proportional to the photoionization cross-section, and terms related to the Natural Ionization Orbital model for Delta-SCF calculations. A set of numerical calculations using the developed models is carried out. Pole strength values computed using the two approaches developed for Delta-SCF calculations demonstrate excellent agreement with an electron propagator theory model.