2025/03/19 by Pak, Sarah, Dada, Muhammed A., Govind, Niranjan +1 · 2 citations
#Chemical Physics (physics.chem-ph) #FOS: Physical sciences
paper · doi:10.48550/arxiv.2503.15462
Spectroscopic techniques based on core-level excitations provide powerful tools for probing molecular and electronic structures with high spatial resolution. However, accurately calculating spectral features at the L or M edges is challenging due to the significant influence of spin-orbit and multiplet effects. While scalar-relativistic effects can be incorporated at minimal computational cost, accounting for spin-orbit interactions requires more complex computational frameworks. In this work, we develop and apply the state-interaction approach, incorporating relativistic effects using the ZORA-Kohn-Sham Hamiltonian, to simulate near-edge soft X-ray absorption spectra for closed-shell transition metal complexes. The computed spin-orbit splittings closely match those obtained from more rigorous methods. This approach provides a practical and cost-effective alternative to more rigorous two-component methods, making it particularly valuable for large-scale calculations and applications such as resonant inelastic X-ray scattering simulations, where capturing a large number of excited states is essential.