RT-EOM-CCSD Calculations of Inner and Outer Valence Ionization Energies and Spectral Functions

Area of Science:

• Quantum chemistry
• Computational physics
• Materials science

Background:

• Photoelectron spectroscopy (PES) is crucial for material characterization but often requires known standards for interpretation.
• Developing theoretical methods is essential for studying unknown or complex material systems.

Purpose of the Study:

• To extend the real-time equation-of-motion coupled cluster (RT-EOM-CC) method to valence photoelectron spectroscopy (PES).
• To provide a reliable theoretical tool for interpreting PES data of unknown materials.

Main Methods:

• Implementation of a real-time equation-of-motion coupled cluster (RT-EOM-CC) approach for valence PES calculations.
• Comparison of RT-EOM-CC results with experimental data and other theoretical methods like configuration interaction (CI).

Main Results:

• The RT-EOM-CC method accurately reproduces ionization energies and spectral functions for valence PES.
• The approach shows good agreement with experimental findings and CI-based calculations, even for highly correlated systems.

Conclusions:

• RT-EOM-CC is a powerful and accurate theoretical method for valence photoelectron spectroscopy.
• This advancement facilitates the characterization of novel and complex materials through PES analysis.