Combining Time-Dependent Density Functional Theory and the ΔSCF Approach for Accurate Core-Electron Spectra

Area of Science:

• Computational materials science
• Quantum chemistry
• Spectroscopy

Background:

• Core-level spectroscopies like X-ray absorption and electron energy loss spectroscopy reveal electronic and chemical structure.
• Interpreting these experimental spectra often requires theoretical support.

Purpose of the Study:

• To assess a first-principles computational approach for interpreting core-level electronic excitation spectra.
• To evaluate the combined linear-response time-dependent density functional theory (TDDFT) and Δ self-consistent field (ΔSCF) method.

Main Methods:

• Utilized TDDFT to compute core-level spectra.
• Shifted TDDFT spectra to align the lowest excitation energy with ΔSCF results.
• Applied the combined method to small molecules.

Main Results:

• The computational approach demonstrated encouraging agreement with experimental spectra.
• The TDDFT/ΔSCF method provides a viable tool for spectral interpretation.

Conclusions:

• The assessed first-principles approach is effective for interpreting core-level electronic excitation spectra.
• This method aids in understanding the electronic and chemical structure of materials through spectroscopy.