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arXiv · 2503.15462

Fast simulation of soft x-ray near-edge spectra using a relativistic state-interaction approach: Application to closed-shell transition metal complexes

Sarah Pak·Muhammed A. Dada·Niranjan Govind·Daniel R. Nascimento
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Abstract

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.

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Sarah Pak, Muhammed A. Dada, Niranjan Govind, Daniel R. Nascimento. 2025-03-19. Fast simulation of soft x-ray near-edge spectra using a relativistic state-interaction approach: Application to closed-shell transition metal complexes. https://doi.org/10.1063/5.0276628

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