Part 1.
1. Different Photoionization Processes, Rydberg Series.
2. Experimental and Theoretical Methods of Photoionization.
3. General Formalism of the Screening Constant by Unit Nuclear Charge Method Applied to Photoionization.

Part 2. Applications in the Calculations of Energies and Natural Widths of the Resonance States of Multi-Electron Atomic Systems
4. Application to the Calculation of Energies of Two-electron Atomic Systems (Helium-like Systems).
5. Calculating the energies of Three-electron Atomic Systems (Lithium-like Systems).
6. Application in the Resonant Photoionization of Atomic Systems of Atomic Numbers Z = 4–12.
7. Resonant Photoionization of Sulfur (S) and Ar+, Se+, Se2+ and Kr+ Ions.

Appendix 1. Detailed Calculation of the Screening Constant by Unit Nuclear Charge Relative to the Ground State of Two-electron Atomic Systems.
Appendix 2. Formalism of Slater’s Atomic Orbital Theory.
Appendix 3. Modified Formalism of the Atomic Orbital Theory.